Merge branch 'drm-fixes-3.15' of git:// into drm-fixes

this is the next pull quested for stashed up radeon fixes for 3.15. As discussed support for Mullins was separated out and will get it's own pull request. Remaining highlights are:
1. Some more patches to better handle PLL limits.
2. Making use of the PFLIP additional to the VBLANK interrupt, otherwise we sometimes miss page flip events.
3. Fix for the UVD command stream parser.
4. Fix for bootup UVD clocks on RV7xx systems.
5. Adding missing error check on dpcd reads.
6. Fixes number of banks calculation on SI.

* 'drm-fixes-3.15' of git://
  drm/radeon: lower the ref * post PLL maximum
  drm/radeon: check that we have a clock before PLL setup
  drm/radeon: drm/radeon: add missing radeon_semaphore_free to error path
  drm/radeon: Fix num_banks calculation for SI
  drm/radeon/dp: check for errors in dpcd reads
  drm/radeon: avoid high jitter with small frac divs
  drm/radeon: check buffer relocation offset
  drm/radeon: use pflip irq on R600+ v2
  drm/radeon/uvd: use lower clocks on old UVD to boot v2