soc/intel/common: Limit BIOS region cache to 16MB

Cache BIOS region can boost boot performance, however it can't be over
16MB, according to processor EDS vol1(Apollolake/Skylake/WhiskeyLake),
FLASH+APIC LT will be less than 20MB under 4G. Set the maxiam to 16GB
to save numbers of mtrr entries.

BUG=b:119267832
TEST=Build and boot up fine on whiskeylake rvp platform.

Change-Id: I46a47c8bf66b14fb2fcb7b6b1d30d02886c450a4
Signed-off-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-on: https://review.coreboot.org/c/29944
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

0 files changed, 0 insertions, 0 deletions