This patch is no longer needed, the upstream Makefile exports CPP from
CPP_FOR_BUILD since 12.1.
(From OE-Core rev: c7546939574dc5e976caae8f0e705b805962ff03)
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>