drm/amdgpu: Program GC registers through RLCG interface in gfx_v11/gmc_v11

drm/amdgpu: Program GC registers through RLCG interface in gfx_v11/gmc_v11

[Why]
L1 blocks most of GC registers accessing by MMIO.

[How]
Use RLCG interface to program GC registers under SRIOV VF in full access time.

Signed-off-by: Yifan Zha <Yifan.Zha@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>