drm/atmel: Drop drm_vblank_cleanup

Again almost correct, but since interrupts are shut down after vblank
still a race. Proper cleanup would call drm_atomic_helper_shutdown to
make sure this really is safe.

v2: Remove misplace malidp hunk (Liviu).

Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170524145212.27837-18-daniel.vetter@ffwll.ch

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c

@@ -678,7 +678,6 @@ static void atmel_hlcdc_dc_unload(struct drm_device *dev)
 	flush_workqueue(dc->wq);
 	drm_kms_helper_poll_fini(dev);
 	drm_mode_config_cleanup(dev);
-	drm_vblank_cleanup(dev);
 
 	pm_runtime_get_sync(dev->dev);
 	drm_irq_uninstall(dev);