Merge tag 'drm-dp-quirk-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux

Merge tag 'drm-dp-quirk-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux

Pull drm displayport quirk support:
 "DP quirk for usb c dongles.

  As mentioned I have a separate request for fixing a regression, but
  also keeping the broken hw working, for certain USB-C DP adapters they
  require a minimised n/m parameters, but an attempt to do this
  generically has failed, we need to quirk these specific adapters.
  However doing it generically regressed some eDP panels.

  This pull adds the infrastructure and a quirk for the adapter"

* tag 'drm-dp-quirk-for-v4.12-rc4' of git://people.freedesktop.org/~airlied/linux:
  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