drivers/intel/gma: Do not rely on CBLV in OpRegion Mailbox3

CBLV is not kept up to date by Linux' i915. We should fix that too,
but it will likely take some years until we can always expect it to
work.

For now read the register values directly. To accomodate that we
are not the only one writing those, revise XBQC() to search for
the closest value in BRIG (instead of a lower equal one) and round
more accurately for better matches.

Change-Id: I4e2d8fa34e75463d4cf7242af3e2c67577cfa2a5
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/28301
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

0 files changed, 0 insertions, 0 deletions