drm/amdgpu: split mmhub v3_0_2 callbacks from mmhub v3_0

So we don't need to add ip version check in every callback
when there is atc related programming that is only
available in mmhub v3_0

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>