drm/meson: Drop drm_vblank_cleanup

Again seems just cargo-culted.

Cc: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170524145212.27837-26-daniel.vetter@ffwll.ch

drivers/gpu/drm/meson/meson_drv.c

@@ -285,7 +285,6 @@ static void meson_drv_unbind(struct device *dev)
 	drm_kms_helper_poll_fini(drm);
 	drm_fbdev_cma_fini(priv->fbdev);
 	drm_mode_config_cleanup(drm);
-	drm_vblank_cleanup(drm);
 	drm_dev_unref(drm);
 
 }