+ * \param[in] layout component layout list.
+ * \param[in] cb callback for each component
+ * \param[in] cbdata callback data
+ *
+ * \retval < 0 error happens during the iteration
+ * \retval LLAPI_LAYOUT_ITER_CONT finished the iteration w/o error
+ * \retval LLAPI_LAYOUT_ITER_STOP got something, stop the iteration