sb/intel/common: Add common code for SMM setup and smihandler

This moves the sandybridge both smm setup and smihandler code to a
common place.

Tested on Thinkpad X220, still boots, resume to and from S3 is fine
so smihandler is still working fine.

Change-Id: I28e2e6ad1e95a9e14462a456726a144ccdc63ec9
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/23427
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
24 files changed