A few fixes for 4.16:
- Fix a backlight S/R regression on amdgpu
- Fix prime teardown on radeon and amdgpu
- DP fix for amdgpu
* 'drm-fixes-4.16' of git://people.freedesktop.org/~agd5f/linux:
drm/amdgpu/dce: Don't turn off DP sink when disconnected
drm/amdgpu: save/restore backlight level in legacy dce code
drm/radeon: fix prime teardown order
drm/amdgpu: fix prime teardown order