Vega20 has dual-UVD. Need Restruct amdgpu_device::uvd to support
multiple uvds. There are no any logical changes here.
Signed-off-by: NJames Zhu <James.Zhu@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>