Add Intel ACPI IGD OpRegion support

This adds the support necessary for allowing ACPI backlight control to
work on some newer Intel-based graphics systems. Tested on Thinkpad T61
and HP 2510p hardware.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Dave Airlie <airlied@linux.ie>
7 files changed