Intel, radeon, exynos fixes.

Intel: fixes a few Ivybridge hangs, along with fixing RC6 on SNB (still
not on, but at least allows for distros to patch it on easily).

radeon: oops reading some files in debugfs that weren't meant to appear,
a fix that touches a lot of files, so looks worse than it is, it fixes
an oops if a GPU reset fails and userspace keeps submitting more data,
along with a minor BIOS fix for newer boards.

exynos: a group of fixes for exynos, they've sent me a few more but
these were all I got through, and its no hw vanilla kernel users see a
lot off yet.

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/kms/atom: dpms bios scratch reg updates
  drm/radeon/kms: properly set accel working flag and bailout when false
  drm/radeon: Only create additional ring debugfs files on Cayman or newer.
  drm/exynos: added postclose to release resource.
  drm/exynos: removed exynos_drm_fbdev_recreate function.
  drm/exynos: fixed page flip issue.
  drm/exynos: added possible_clones setup function.
  drm/exynos: removed pageflip_event_list init code when closed.
  drm/exynos: changed priority of mixer layers.
  drm/exynos: Fix typo in exynos_mixer.c
  drm/i915: do not enable RC6p on Sandy Bridge
  drm/i915: gen7: Disable the RHWO optimization as it can cause GPU hangs.
  drm/i915: gen7: work around a system hang on IVB
  drm/i915: gen7: Implement an L3 caching workaround.
  drm/i915: gen7: implement rczunit workaround