drm/amd/display: Migrate DCCG register access from hwseq to dccg component.

drm/amd/display: Migrate DCCG register access from hwseq to dccg component.

[why]
Direct DCCG register access in hwseq layer was creating register conflicts.

[how]
Migrated DCCG registers from hwseq to dccg component.

Reviewed-by: Martin Leung <martin.leung@amd.com>
Signed-off-by: Bhuvanachandra Pinninti <bpinnint@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>