Expose terminate_dlg through C API

modules_k/dialog/dlg_load.h

@@ -34,8 +34,11 @@
 
 struct dlg_binds {
 	register_dlgcb_f  register_dlgcb;
+	terminate_dlg_f terminate_dlg;
 };
 
+/* terminate_dlg function prototype */
+typedef int (*terminate_dlg_f)(struct dlg_cell* dlg, str *hdrs);
 
 typedef int(*load_dlg_f)( struct dlg_binds *dlgb );
 int load_dlg( struct dlg_binds *dlgb);