cpu/Makefile.inc: Only inculde x86 subdir if ARCH_x86 is selected

There is no other guard to prevent this from being picked up when
building for other architectures.

Change-Id: I2039a289a4dd9970d5dd0f90d43d5d5c2a6d0a0b
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/11795
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
1 file changed