Fix i915 shutdown warning logs

Maybe there is no display in VM, the dmc would not be initialized,
hence don't need to suspend dmc in i915 shutdown

Tracked-On: OAM-120011
Signed-off-by: Wenkui <kui.wen@intel.com>

drivers/gpu/drm/i915/i915_driver.c

@@ -1055,7 +1055,8 @@ void i915_driver_shutdown(struct drm_i915_private *i915)
 	intel_suspend_encoders(i915);
 	intel_shutdown_encoders(i915);
 
-	intel_dmc_suspend(i915);
+	if (HAS_DISPLAY(i915))
+		intel_dmc_suspend(i915);
 
 	i915_gem_suspend(i915);