drm/amdgpu/powerplay: add smu block for sienna_cichlid

Add SMU block for sienna_cichlid with psp load type.

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