drivers/intel/gma: Fix OpRegion Mailbox3 backlight change

We should always update BCLP, no matter if the driver is ready yet to
process the request. This way it will hold the current value when the
driver initializes.

Change-Id: I4b091d744f95da39abe542966f0a8589a187573b
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/28300
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
1 file changed