Fixes for 4.19:
- Fix UVD 7.2 instance handling
- Fix UVD 7.2 harvesting
- GPU scheduler fix for when a process is killed
- TTM cleanups
- amdgpu CS bo_list fixes
- Powerplay fixes for polaris12 and CZ/ST
- DC fixes for link training certain HMDs
- DC fix for vega10 blank screen in certain cases