Initial pull request for DC support.  We've completed a substantial amount of
the cleanup and restructuring in our TODO.  There are a few additional
cleanups that we are continuing to work on, but I don't think there are any
showstoppers remaining. We've tried to maintain most of the history for bisect
purposes.  Harry made sure all the commits build.  We've enabled DC for vega10
and Raven.  Pre-vega10 parts can be enabled via module parameter (amdgpu.dc=1),
but are not enabled by default at this point until we get further testing
upstream.

This code provides atomic modesetting support for DCE8 (CIK), DCE10 (Tonga,
Fiji), DCE11 (CZ, ST, Polaris), DCE12 (vega10), and DCN1 (RV) including
HDMI and DP audio, DP MST, and many other advanced display features.

+

Latest cleanups for DC from you and Harry.  Note that there is some
flickering on some older asics with this branch due to a regression in powerplay
that has already been fixed and will be included in my next non-DC pull request
next week.

* 'drm-next-4.15-dc' of git://people.freedesktop.org/~agd5f/linux: (897 commits)
  amdgpu/dc: use kref for dc_state.
  amdgpu/dc: convert dc_sink to kref.
  amdgpu/dc: convert dc_stream_state to kref.
  amdgpu/dc: use kref for dc_plane_state.
  amdgpu/dc: convert dc_gamma to kref reference counting.
  amdgpu/dc: convert dc_transfer to use a kref.
  amdgpu/dc: kill a bunch of dead code.
  amdgpu/dc: set a bunch of functions to static.
  amdgpu/dc: kill some deadcode in dc core.
  amdgpu/dc: fix indentation on a couple of returns.
  amdgpu/dm: don't use after free.
  amdgpu/dc: kfree already checks for NULL.
  amdgpu/dc: fix a bunch of misc whitespace.
  amdgpu/dc: drop hw_sequencer_types.h
  amdgpu/dc: drop dce110_types.h
  amdgpu/dc: use kernel ilog2 for log_2.
  amdgpu/dc: don't memset after kzalloc.
  amdgpu/dc: inline dal grph object id functions.
  amdgpu/dc: inline dml_round_to_multiple
  amdgpu/dc: rename bios get_image symbol to something more searchable.
  ...