modules: openthread: fix doxygen for openthread_set_nat64_receive_cb

Fix include guards and better document the kconfig dependency

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

modules/openthread/include/openthread.h

@@ -133,17 +133,19 @@ int openthread_stop(void);
  */
 void openthread_set_receive_cb(openthread_receive_cb cb, void *context);
 
+#if defined(CONFIG_OPENTHREAD_NAT64_TRANSLATOR) || defined(__DOXYGEN__)
 /**
  * @brief Set the additional callback for receiving NAT64 translated packets.
  *
  * @details This callback is called once a packet from OpenThread NAT64 translator
  * is received and can be used to inject packets into the Zephyr networking stack.
  * Setting this callback is optional.
  *
+ * @kconfig_dep{CONFIG_OPENTHREAD_NAT64_TRANSLATOR}
+ *
  * @param cb Callback to set.
  * @param context Context to pass to the callback.
  */
-#if defined(CONFIG_OPENTHREAD_NAT64_TRANSLATOR)
 void openthread_set_nat64_receive_cb(openthread_receive_cb cb, void *context);
 #endif /* CONFIG_OPENTHREAD_NAT64_TRANSLATOR */