Merge tag 'topic/dp-quirks-2017-05-31' of git://anongit.freedesktop.org/git/drm-intel...

Merge tag 'topic/dp-quirks-2017-05-31' of git://anongit.freedesktop.org/git/drm-intel into drm-fixes

DP sink specific quirks

* tag 'topic/dp-quirks-2017-05-31' of git://anongit.freedesktop.org/git/drm-intel:
  drm/i915: Detect USB-C specific dongles before reducing M and N
  drm/dp: start a DPCD based DP sink/branch device quirk database
  drm/i915: use drm DP helper to read DPCD desc
  drm/dp: add helper for reading DP sink/branch device desc from DPCD