drm/amdgpu: Allow GfxOff on Vangogh as default

Send allow GfxOff message to SMU to enter GfxOff
mode as default.
Signed-off-by: Jinzhou Su <Jinzhou.Su@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v10_0.c

@@ -7905,6 +7905,7 @@ static int gfx_v10_0_set_powergating_state(void *handle,
 		break;
 	case CHIP_VANGOGH:
 		gfx_v10_cntl_pg(adev, enable);
+		amdgpu_gfx_off_ctrl(adev, enable);
 		break;
 	default:
 		break;