Update ivybridge graphics initialization

- Add config options to set backlight registers
- Update powermeter weight tables for IvyBridge GT1 and
add a new table for GT2 SKU
- Fix a few registers used during GPU PM init sequence

Change-Id: I1500bc07e3ba1bc10c77e7856089e716489dc07a
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/973
Tested-by: build bot (Jenkins)
2 files changed