drm/amdgpu/SRIOV: Navi10/12 VF doesn't support SMU

In SRIOV case, SMU and powerplay are handled in HV.

VF shouldn't have control over SMU and powerplay.

Signed-off-by: Jiange Zhao <Jiange.Zhao@amd.com>
Reviewed-by: Emily Deng <Emily.Deng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>