northbridge/intel: move mrc_cache definition into a common header

The mrc_cache definition and the struct mrc_container are the same
over all intel platforms.

Change-Id: I128a4b5693d27ead709325c597ffe68a0cc78bab
Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
Reviewed-on: https://review.coreboot.org/13998
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
11 files changed