Re-sync all files under the scripts/kconfig directory with
Linux 4.10.
Some parts include U-Boot own modification. I made sure to not
revert the following commits:
5b8031ccb4 ("Add more SPDX-License-Identifier tags")
192bc6948b ("Fix GCC format-security errors and convert sprintfs.")
da58dec866 ("Various Makefiles: Add SPDX-License-Identifier tags")
20c20826ef ("Kconfig: Enable usage of escape char '\' in string values")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>