soc/intel/common/mrc_cache: Don't assume FMAP is tied to CHROMEOS

The old code only checked for an RW_MRC_CACHE region when
CONFIG_CHROMEOS was selected. This assumption is not necessarily true,
as one can have FMAP without a CHROMEOS build. As a result, always
search FMAP first before falling back on CBFS for locating the MRC
cache region.
The old logic where CHROMEOS builds would fail when RW_MRC_CACHE was
not found is preserved, such that behavior does not change.

Change-Id: I3596ef3235eff661af055968ea641f3e9671cdcd
Signed-off-by: Alexandru Gagniuc <alexandrux.gagniuc@intel.com>
Reviewed-on: https://review.coreboot.org/14757
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
1 file changed