drm/amd/display: Reverted DSC programming sequence change

[HOW&WHY]
Revert a previous commit by moving DSC programming back to before link
enablement.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Jayendran Ramani <Jayendran.Ramani@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Nagulendran, Iswara <Iswara.Nagulendran@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>