drm/amd/display: Trigger full update after DCC on/off

[Why]
During DCC on/off, stutter period is calculated before DCC has fully transitioned.
This results in incorrect stutter period calculation.

[How]
Trigger a full update when DCC changes between on/off.

Signed-off-by: Jake Wang <haonan.wang2@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>