samples: usb: midi: use correct Class Code triple

USB MIDI2 implementation has IAD and should use an appropriate triple to
indicate it.

Signed-off-by: Johann Fischer <[email protected]>

Author: jfischer-no

samples/subsys/usb/common/sample_usbd_init.c

@@ -79,6 +79,7 @@ static void sample_fix_code_triple(struct usbd_context *uds_ctx,
 	if (IS_ENABLED(CONFIG_USBD_CDC_ACM_CLASS) ||
 	    IS_ENABLED(CONFIG_USBD_CDC_ECM_CLASS) ||
 	    IS_ENABLED(CONFIG_USBD_CDC_NCM_CLASS) ||
+	    IS_ENABLED(CONFIG_USBD_MIDI2_CLASS) ||
 	    IS_ENABLED(CONFIG_USBD_AUDIO2_CLASS)) {
 		/*
 		 * Class with multiple interfaces have an Interface