drm/amdgpu: implement smuio v11_0_6 callbacks

Implement smuio v11_0_6 callbacks which will used by Sienna_Cichlid and
forward ASIC.

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