drm: add register and unregister functions for connectors

Introduce generic functions to register and unregister connectors. This
provides a common place to add and remove associated user space
interfaces.

Signed-off-by: Thomas Wood <thomas.wood@intel.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index efd3cf5..dbabaec 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12234,7 +12234,7 @@
 	struct drm_connector *connector = &intel_connector->base;
 
 	intel_panel_destroy_backlight(connector);
-	drm_sysfs_connector_remove(connector);
+	drm_connector_unregister(connector);
 }
 
 void intel_modeset_cleanup(struct drm_device *dev)