drm/amdgpu: indirect register access for nv12 sriov

1. expand rlcg interface for gc & mmhub indirect access
2. add rlcg interface for no kiq

v2: squash in fix for gfx9 (Changfeng)

Signed-off-by: Peng Ju Zhou <PengJu.Zhou@amd.com>
Reviewed-by: Emily.Deng <Emily.Deng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>