drm/amd/amdgpu: Enable clockgating for UVD5 on Tonga

This patch enables clock gating for the UVD5 block with
Tonga.
Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/vi.c

@@ -1081,7 +1081,7 @@ static int vi_common_early_init(void *handle)
 		adev->external_rev_id = adev->rev_id + 0x3c;
 		break;
 	case CHIP_TONGA:
-		adev->cg_flags = 0;
+		adev->cg_flags = AMD_CG_SUPPORT_UVD_MGCG;
 		adev->pg_flags = 0;
 		adev->external_rev_id = adev->rev_id + 0x14;
 		break;