These patches re-enable GFX PG on Stoney and Carrizo. I've found that AMD_PG_SUPPORT_CP and AMD_PG_SUPPORT_RLC_SMU_HS are both buggy so they are disabled. RLC_SMU_HS results in early system hangs whereas CP powergating results in harder to trigger system hangs. With both disabled I've been able to stress test GFX without hangs. The UVD PG is only enabled if powerplay is disabled. Tested by sampling with the debug tool I can see correct behaviour in the PGFSM TILE registers.
