fix(openthread): handle SetTimeSyncState when ifconfig up or down

components/openthread/private_include/esp_openthread_radio.h

@@ -44,6 +44,14 @@ void esp_openthread_radio_deinit(void);
  */
 void esp_openthread_radio_update(esp_openthread_mainloop_context_t *mainloop);
 
+/**
+ * @brief This function handles netif change for radio spinel.
+ *
+ * @param[in]    state    The updated netif state.
+ *
+ */
+void esp_openthread_handle_netif_state_change(bool state);
+
 /**
  * @brief This function performs the OpenThread radio process.
  *