Ready to implement sync function on ESP32 device

esp32_device/main/secure_api.h

@@ -40,6 +40,13 @@ extern "C"
      */
     char *secure_api_get_dev_certificate();
 
+    /**
+     * Synchronise device with central backend
+     *
+     * Returns NULL in case of failure
+     */
+    void *secure_api_sync_device();
+
 #ifdef __cplusplus
 }
 #endif