drm/amd/pm: not stop rlc for IMU enabled APUs when suspend

For IMU enabled APUs, after sending the PrepareMp1ForUnload message
to SMU in system_features_control, the RLC registers can't be touched.
The driver to stop the rlc in suspending is no longer required.
Signed-off-by: Tim Huang <Tim.Huang@amd.com>
Reviewed-by: Yifan Zhang <yifan1.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c

@@ -1711,6 +1711,7 @@ static int smu_disable_dpms(struct smu_context *smu)
 	}
 
 	if (amdgpu_ip_version(adev, GC_HWIP, 0) >= IP_VERSION(9, 4, 2) &&
+	    !((adev->flags & AMD_IS_APU) && adev->gfx.imu.funcs) &&
 	    !amdgpu_sriov_vf(adev) && adev->gfx.rlc.funcs->stop)
 		adev->gfx.rlc.funcs->stop(adev);