scripts/dtc: Re-sync with Linux 4.17-rc4

To achieve a DTC state (more or less) equivalent to Linux 4.17-rc4,
backport the DTC-specific part from below Linux commits:

b23d1a241f4eb4 ("kbuild: add %.lex.c and %.tab.[ch] to 'targets' automatically")
9a8dfb394c0467 ("kbuild: clean up *.lex.c and *.tab.[ch] patterns from top-level Makefile")
59889300274569 (".gitignore: move *.lex.c *.tab.[ch] patterns to the top-level .gitignore")
e039139be8c251 ("scripts/dtc: generate lexer and parser during build instead of shipping")
b24413180f5600 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license")

With this commit, the diff between Linux and U-boot common DTC files is:
$ git diff --stat --diff-filter=M v4.17-rc4 <this-commit> -- scripts/dtc
  scripts/dtc/.gitignore | 2 +-
  scripts/dtc/Makefile   | 3 +++

The delta is coming from U-boot commits:
* v2017.11 de163ecedb ("scripts: dtc: Add .gitignore")
* v2018.01 15b97f5c5e ("pylibfdt: move pylibfdt to scripts/dtc/pylibfdt and refactor makefile")

Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/dtc/.gitignore

@@ -1,4 +1 @@
 /dtc
-/dtc-lexer.lex.c
-/dtc-parser.tab.c
-/dtc-parser.tab.h

scripts/dtc/Makefile

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # scripts/dtc makefile
 
 hostprogs-y	:= dtc
@@ -27,8 +28,5 @@ HOSTCFLAGS_dtc-parser.tab.o := $(HOSTCFLAGS_DTC)
 # dependencies on generated files need to be listed explicitly
 $(obj)/dtc-lexer.lex.o: $(obj)/dtc-parser.tab.h
 
-# generated files need to be cleaned explicitly
-clean-files	:= dtc-lexer.lex.c dtc-parser.tab.c dtc-parser.tab.h
-
 # Added for U-Boot
 subdir-$(CONFIG_PYLIBFDT) += pylibfdt

scripts/dtc/dtc-parser.tab.h_shipped

@@ -1,125 +0,0 @@
-/* A Bison parser, made by GNU Bison 3.0.4.  */
-
-/* Bison interface for Yacc-like parsers in C
-
-   Copyright (C) 1984, 1989-1990, 2000-2015 Free Software Foundation, Inc.
-
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation, either version 3 of the License, or
-   (at your option) any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-/* As a special exception, you may create a larger work that contains
-   part or all of the Bison parser skeleton and distribute that work
-   under terms of your choice, so long as that work isn't itself a
-   parser generator using the skeleton or a modified version thereof
-   as a parser skeleton.  Alternatively, if you modify or redistribute
-   the parser skeleton itself, you may (at your option) remove this
-   special exception, which will cause the skeleton and the resulting
-   Bison output files to be licensed under the GNU General Public
-   License without this special exception.
-
-   This special exception was added by the Free Software Foundation in
-   version 2.2 of Bison.  */
-
-#ifndef YY_YY_DTC_PARSER_TAB_H_INCLUDED
-# define YY_YY_DTC_PARSER_TAB_H_INCLUDED
-/* Debug traces.  */
-#ifndef YYDEBUG
-# define YYDEBUG 0
-#endif
-#if YYDEBUG
-extern int yydebug;
-#endif
-
-/* Token type.  */
-#ifndef YYTOKENTYPE
-# define YYTOKENTYPE
-  enum yytokentype
-  {
-    DT_V1 = 258,
-    DT_PLUGIN = 259,
-    DT_MEMRESERVE = 260,
-    DT_LSHIFT = 261,
-    DT_RSHIFT = 262,
-    DT_LE = 263,
-    DT_GE = 264,
-    DT_EQ = 265,
-    DT_NE = 266,
-    DT_AND = 267,
-    DT_OR = 268,
-    DT_BITS = 269,
-    DT_DEL_PROP = 270,
-    DT_DEL_NODE = 271,
-    DT_PROPNODENAME = 272,
-    DT_LITERAL = 273,
-    DT_CHAR_LITERAL = 274,
-    DT_BYTE = 275,
-    DT_STRING = 276,
-    DT_LABEL = 277,
-    DT_REF = 278,
-    DT_INCBIN = 279
-  };
-#endif
-
-/* Value type.  */
-#if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
-
-union YYSTYPE
-{
-#line 39 "dtc-parser.y" /* yacc.c:1909  */
-
-	char *propnodename;
-	char *labelref;
-	uint8_t byte;
-	struct data data;
-
-	struct {
-		struct data	data;
-		int		bits;
-	} array;
-
-	struct property *prop;
-	struct property *proplist;
-	struct node *node;
-	struct node *nodelist;
-	struct reserve_info *re;
-	uint64_t integer;
-	unsigned int flags;
-
-#line 99 "dtc-parser.tab.h" /* yacc.c:1909  */
-};
-
-typedef union YYSTYPE YYSTYPE;
-# define YYSTYPE_IS_TRIVIAL 1
-# define YYSTYPE_IS_DECLARED 1
-#endif
-
-/* Location type.  */
-#if ! defined YYLTYPE && ! defined YYLTYPE_IS_DECLARED
-typedef struct YYLTYPE YYLTYPE;
-struct YYLTYPE
-{
-  int first_line;
-  int first_column;
-  int last_line;
-  int last_column;
-};
-# define YYLTYPE_IS_DECLARED 1
-# define YYLTYPE_IS_TRIVIAL 1
-#endif
-
-
-extern YYSTYPE yylval;
-extern YYLTYPE yylloc;
-int yyparse (void);
-
-#endif /* !YY_YY_DTC_PARSER_TAB_H_INCLUDED  */

scripts/dtc/update-dtc-source.sh

@@ -1,9 +1,10 @@
 #!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
 # Simple script to update the version of DTC carried by the Linux kernel
 #
 # This script assumes that the dtc and the linux git trees are in the
 # same directory. After building dtc in the dtc directory, it copies the
-# source files and generated source files into the scripts/dtc directory
+# source files and generated source file(s) into the scripts/dtc directory
 # in the kernel and creates a git commit updating them to the new
 # version.
 #
@@ -33,7 +34,6 @@ DTC_LINUX_PATH=`pwd`/scripts/dtc
 DTC_SOURCE="checks.c data.c dtc.c dtc.h flattree.c fstree.c livetree.c srcpos.c \
 		srcpos.h treesource.c util.c util.h version_gen.h Makefile.dtc \
 		dtc-lexer.l dtc-parser.y"
-DTC_GENERATED="dtc-lexer.lex.c dtc-parser.tab.c dtc-parser.tab.h"
 LIBFDT_SOURCE="Makefile.libfdt fdt.c fdt.h fdt_addresses.c fdt_empty_tree.c \
 		fdt_overlay.c fdt_ro.c fdt_rw.c fdt_strerror.c fdt_sw.c \
 		fdt_wip.c libfdt.h libfdt_env.h libfdt_internal.h"
@@ -58,10 +58,6 @@ for f in $DTC_SOURCE; do
 	cp ${DTC_UPSTREAM_PATH}/${f} ${f}
 	git add ${f}
 done
-for f in $DTC_GENERATED; do
-	cp ${DTC_UPSTREAM_PATH}/$f ${f}_shipped
-	git add ${f}_shipped
-done
 for f in $LIBFDT_SOURCE; do
        cp ${DTC_UPSTREAM_PATH}/libfdt/${f} libfdt/${f}
        git add libfdt/${f}