misc i915 fixes, mostly all stable material as well.
* tag 'drm-intel-fixes-2015-01-29' of git://anongit.freedesktop.org/drm-intel:
drm/i915: BDW Fix Halo PCI IDs marked as ULT.
drm/i915: Fix and clean BDW PCH identification
drm/i915: Only fence tiled region of object.
drm/i915: fix inconsistent brightness after resume
drm/i915: Init PPGTT before context enable