drm/modeset: add helper to unplug all connectors from sysfs

In order to get correct ordering at hot-unplug for userspace,
we need to tear down all the sysfs bits at the correct time.

This adds a helper to allow drivers to remove the sysfs nodes
for all connectors.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 9595c2c..3401761 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -826,6 +826,8 @@
 			      int connector_type);
 
 extern void drm_connector_cleanup(struct drm_connector *connector);
+/* helper to unplug all connectors from sysfs for device */
+extern void drm_connector_unplug_all(struct drm_device *dev);
 
 extern int drm_encoder_init(struct drm_device *dev,
 			    struct drm_encoder *encoder,