Some fixes from Intel.
* tag 'drm-intel-fixes-2014-04-11' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Always use kref tracking for all contexts.
drm/i915: do not setup backlight if not available according to VBT
drm/i915: check VBT for supported backlight type
drm/i915: Disable self-refresh for untiled fbs on i915gm
drm/mm: Don't WARN if drm_mm_reserve_node