drm/amd/display: Apply DML21 Patches

[Why & How]
Add several DML21 fixes

Reviewed-by: Wenjing Liu <wenjing.liu@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>