Patch merged into coreboot/master: mainboard/google/reef: clear normal MRC cache on recovery retrain

the following patch was just integrated into master:
commit f8bd1dd43cadc01cd93b6f14373d3fd3903d5817
Author: Aaron Durbin 
Date:   Wed Dec 14 15:41:45 2016 -0600

mainboard/google/reef: clear normal MRC cache on recovery retrain

For Chrome OS the normal MRC cache should be cleared when a hardware
    retrain recovery request is observed. The reason is that since there
    are 2 different MRC cache slots there needs to be a mechanism which
    allows an end user make a system bootable again if the MRC settings
    happen to not allow the system to boot any longer. Therefore, one
    just needs to enter recovery with the hardware retrain flag and
    the system normal MRC cache slot will be invalidated.

BUG=chrome-os-partner:60592
    BRANCH=reef

Change-Id: I6ad32ed0dd217d66404b77467a88689a06044544
    Signed-off-by: Aaron Durbin 
    Reviewed-on: https://review.coreboot.org/17871
    Tested-by: build bot (Jenkins)
    Reviewed-by: Furquan Shaikh

See https://review.coreboot.org/17871 for details.

-gerrit