gma500: intel_bios updates

Pull in various i915 bits that we will need to begin tackling the LVDS detect
and ACPI events. We try and drift towards the i915 version of the code with
the long term goal that at least some of it can one day be unified.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>