Recent kernel versions run flex and bison to generate lexers and
parsers from real source files such as *.l and *.y . This provides
better maintainability than version-controlling pre-generated C files
with a "_shipped" suffix.

This commit imports flex and bison rules from Linux, and deletes
pre-generated parsers and lexers.

Refer to the following commits in Linux:

 - 033dba2ec06c ("kbuild: prepare to remove C files pre-generated by
   flex and bison")

 - 29c833061c1d ("kconfig: generate lexer and parser during build
   instead of shipping")

 - e039139be8c2 ("scripts/dtc: generate lexer and parser during
   build instead of shipping")

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>