ns2: vty: on `show ns` add information of NS binds

Change-Id: I6cef42749555e577d5573f2ed8b8bce4cf842a98
diff --git a/src/gb/gprs_ns2_internal.h b/src/gb/gprs_ns2_internal.h
index 3d0f96d..f5d9ed5 100644
--- a/src/gb/gprs_ns2_internal.h
+++ b/src/gb/gprs_ns2_internal.h
@@ -192,8 +192,11 @@
 
 	/*! free the vc priv data */
 	void (*free_vc)(struct gprs_ns2_vc *nsvc);
-};
 
+	/*! allow to show information for the vty */
+	void (*dump_vty)(const struct gprs_ns2_vc_bind *bind,
+			 struct vty *vty, bool stats);
+};
 
 struct gprs_ns2_vc_driver {
 	const char *name;