drm/amd/display: Add connector to the state if DSC debugfs is set

[why]
We want to trigger atomic check on connector, which DSC debugfs
properties have changed.

[how]
Add a helper function that iterates through all active connectors
and add them to the state if DSC debugfs parameters have changed.

Signed-off-by: Eryk Brol <eryk.brol@amd.com>
Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>