drm/amd/display: combine dirty rectangles in DMUB FW

[why]
In PSR-SU design, the DMUB FW handles the combination of multiple
dirty rectangles.

[how]
- create DC dmub update dirty rectangle helper which sends the
  dirty rectangles per pipe from DC to DMUB, and DMUB FW will
  handle to combine the dirty RECTs
- call the helper from DC commit plane update function.

Signed-off-by: David Zhang <dingchen.zhang@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>