console/post: Split parts to arch/

Both IO port and cmos are currently arch/x86 only features.

Change-Id: I010af3f645c0be38dd856657874c36103aebbdc2
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38187
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/Makefile.inc

@@ -99,6 +99,7 @@ all-y += boot.c
 all-y += memcpy.c
 all-y += memset.c
 all-y += cpu_common.c
+all-y += post.c
 
 endif