Merge branch 'drm-fixes-4.16' of git://people.freedesktop.org/~agd5f/linux into drm-fixes

- Powerplay fixes for cards with no displays attached
- Couple of DC fixes
- radeon workaround for PPC64

* 'drm-fixes-4.16' of git://people.freedesktop.org/~agd5f/linux:
  drm/radeon: insist on 32-bit DMA for Cedar on PPC64/PPC64LE
  drm/amd/display: VGA black screen from s3 when attached to hook
  drm/amdgpu: Unify the dm resume calls into one
  drm/amdgpu: Add a missing lock for drm_mm_takedown
  Revert "drm/radeon/pm: autoswitch power state when in balanced mode"
  drm/amd/powerplay/smu7: allow mclk switching with no displays
  drm/amd/powerplay/vega10: allow mclk switching with no displays