drm/amd/display: Do full modeset when DSC debugfs is changed

[Why]
Whenever DSC parameters are changed we need to perform full modeset to commit
DSC changes to DC.

[How]
If dsc_force_changed is set, need to set mode_changed on new CRTC state

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