drm/amdgpu: enable gfx clockgating for ST (v2)

v2: just enable MGCG for now since CGCG causes hangs

Acked-by: Tom St Denis <tom.stdenis@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c b/drivers/gpu/drm/amd/amdgpu/vi.c
index c9c88a5..2a7d37a 100644
--- a/drivers/gpu/drm/amd/amdgpu/vi.c
+++ b/drivers/gpu/drm/amd/amdgpu/vi.c
@@ -1114,7 +1114,9 @@
 		adev->external_rev_id = adev->rev_id + 0x1;
 		break;
 	case CHIP_STONEY:
-		adev->cg_flags = AMD_CG_SUPPORT_UVD_MGCG;
+		adev->cg_flags = AMD_CG_SUPPORT_UVD_MGCG |
+			AMD_CG_SUPPORT_GFX_MGCG |
+			AMD_CG_SUPPORT_GFX_MGLS;
 		adev->pg_flags = 0;
 		adev->external_rev_id = adev->rev_id + 0x1;
 		break;