For vega20, there are two UVD rings which share one powerplay instance. Under some case(two rings used parallel), the uvd dpm is disabled twice which causes the SMC hang. Signed-off-by: Evan Quan <evan.quan@amd.com> Reviewed-by: Rex Zhu <rezhu@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>