add ble disconnect

include/zble_module.h

@@ -33,5 +33,6 @@ void zble_module_reglistener(zble_event_listener_t event_listener);
 void zble_module_start_adv();
 void zble_module_stop_adv();
 bool zble_module_is_connected();
+bool zble_module_disconnect();
 
 int32_t zble_module_get_mtu_size();

src/zble_module.c

@@ -449,3 +449,8 @@ void zble_module_init(zble_module_cfg_t *cfg)
 }
 
 int32_t zble_module_get_mtu_size() { return m_mtu_size; }
+
+bool zble_module_disconnect(){
+  ble_conn_state_for_each_connected(disconnect, NULL);
+  return true;
+}