drm/amd/display: Unlock Pipes Based On DET Allocation

drm/amd/display: Unlock Pipes Based On DET Allocation

[Why]
DML21 does not allocate DET evenly between pipes.
May result in underflow when unlocking the pipes as DET could
be overallocated.

[How]
1. Unlock pipes that have a decreased amount of DET allocation
2. Wait for the double buffer to be updated.
3. Unlock the remaining pipes.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Austin Zheng <Austin.Zheng@amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>