append_config
err = append_config(config, *d);
err = append_config(config, jack);
err = append_config(config, jack);
err = append_config(config, &midi2_midi2_ep_out_desc[i]);
err = append_config(config, &midi2_midi2_ep_out_ss_comp_desc);
err = append_config(config, &midi2_midi2_ep_out_class_desc[i]);
err = append_config(config, &midi2_midi2_ep_in_desc[i]);
err = append_config(config, &midi2_midi2_ep_in_ss_comp_desc);
err = append_config(config, &midi2_midi2_ep_in_class_desc[i]);