mainboard/google/reef: add MKBP EC event as SCI event.

Add MKBP as a SCI event: the EC is then able to send events coming from
the sensors.

BUG=b:27849483
TEST=With EC configure to send MKBP events, check sensor information are
retrieved by the kernel.

Change-Id: Ib06241bfcdc8567769baff4f3371cc0c6eab3944
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://review.coreboot.org/16594
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
1 file changed