amdgpu: Add mmhub MGCG and MGLS for vangogh

Add AMD_CG_SUPPORT_MC_MGCG and AMD_CG_SUPPORT_MC_LS

Signed-off-by: Jinzhou.Su <Jinzhou.Su@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>