drm/amdgpu: add MMHUB Clock Gating support for yellow carp

Add AMD_CG_SUPPORT_MC_MGCG/AMD_CG_SUPPORT_MC_LS support.

Signed-off-by: Aaron Liu <aaron.liu@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>