Enable the recovery cache to speed up recovery flows. Also enable clearing of the normal mrc cache on recovery forced retrains. BUG=b:77871444 TEST=went into recovery twice. 2nd time it boots faster. Change-Id: Idfce42ac835637fa521545fadfedecd65df91d4c Signed-off-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: https://review.coreboot.org/25613 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Justin TerAvest <teravest@chromium.org> Reviewed-by: Furquan Shaikh <furquan@google.com>