Arcturus has dual-VCN. Need Restruct amdgpu_device::vcn to support
multiple vcns. There are no any logical changes here
Signed-off-by: NJames Zhu <James.Zhu@amd.com>
Reviewed-by: NLeo Liu <leo.liu@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>