More radeon and amdgpu changes for 4.9. Highlights:
- Initial SI support for amdgpu (controlled by a Kconfig option)
- misc ttm cleanups
- runtimepm fixes
- S3/S4 fixes
- power improvements
- lots of code cleanups and optimizations

* 'drm-next-4.9' of git://people.freedesktop.org/~agd5f/linux: (151 commits)
  drm/ttm: remove cpu_address member from ttm_tt
  drm/radeon/radeon_device: remove unused function
  drm/amdgpu: clean function declarations in amdgpu_ttm.c up
  drm/amdgpu: use the new ring ib and dma frame size callbacks (v2)
  drm/amdgpu/vce3: add ring callbacks for ib and dma frame size
  drm/amdgpu/vce2: add ring callbacks for ib and dma frame size
  drm/amdgpu/vce: add common ring callbacks for ib and dma frame size
  drm/amdgpu/uvd6: add ring callbacks for ib and dma frame size
  drm/amdgpu/uvd5: add ring callbacks for ib and dma frame size
  drm/amdgpu/uvd4.2: add ring callbacks for ib and dma frame size
  drm/amdgpu/sdma3: add ring callbacks for ib and dma frame size
  drm/amdgpu/sdma2.4: add ring callbacks for ib and dma frame size
  drm/amdgpu/cik_sdma: add ring callbacks for ib and dma frame size
  drm/amdgpu/si_dma: add ring callbacks for ib and dma frame size
  drm/amdgpu/gfx8: add ring callbacks for ib and dma frame size
  drm/amdgpu/gfx7: add ring callbacks for ib and dma frame size
  drm/amdgpu/gfx6: add ring callbacks for ib and dma frame size
  drm/amdgpu/ring: add an interface to get dma frame and ib size
  drm/amdgpu/sdma3: drop unused functions
  drm/amdgpu/gfx6: drop gds_switch callback
  ...