add class driver deinit

src/class/net/net_device.h

@@ -105,6 +105,7 @@ void tud_network_link_state_cb(bool state);
 // INTERNAL USBD-CLASS DRIVER API
 //--------------------------------------------------------------------+
 void     netd_init            (void);
+bool     netd_deinit          (void);
 void     netd_reset           (uint8_t rhport);
 uint16_t netd_open            (uint8_t rhport, tusb_desc_interface_t const * itf_desc, uint16_t max_len);
 bool     netd_control_xfer_cb (uint8_t rhport, uint8_t stage, tusb_control_request_t const * request);