The platform_data definitions are generally referenced from both
drivers and board files. That is why header files defining
platform_data sturectures are placed in "include" directory,
but our top level "include" directory is already too cluttered.
Let's collect platform_data definitions under the directory
"include/dm/platform_data" like Linux gathers ones around under
"include/linux/platform_data".
This commit moves two header files:
include/serial_mxc.h -> include/dm/platform_data/serial_mxc.h
include/serial_pl01x.h -> include/dm/platform_data/serial_pl01x.h
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>