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/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index 114aee9..9896286 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -829,7 +829,7 @@
 {
 	struct ast_connector *ast_connector = to_ast_connector(connector);
 	ast_i2c_destroy(ast_connector->i2c);
-	drm_sysfs_connector_remove(connector);
+	drm_connector_unregister(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
@@ -871,7 +871,7 @@
 	connector->interlace_allowed = 0;
 	connector->doublescan_allowed = 0;
 
-	drm_sysfs_connector_add(connector);
+	drm_connector_register(connector);
 
 	connector->polled = DRM_CONNECTOR_POLL_CONNECT;