Open GFX MGCG, CGCG and 3DCG for sienna_cichlid.
Signed-off-by: Likun Gao <Likun.Gao@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>