[ALSA] usb-audio - add support for Miditech USB MIDI keyboards

USB generic driver
Add support for Miditech Midistart and MidiStudio keyboards (another
case of devices using the standard protocol but having no descriptors).

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
diff --git a/sound/usb/usbmidi.c b/sound/usb/usbmidi.c
index 5c75487..5778a9b 100644
--- a/sound/usb/usbmidi.c
+++ b/sound/usb/usbmidi.c
@@ -1515,6 +1515,9 @@
 			       sizeof(snd_usb_midi_endpoint_info_t));
 			err = snd_usbmidi_detect_endpoints(umidi, &endpoints[0], 1);
 			break;
+		case QUIRK_MIDI_MIDITECH:
+			err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints);
+			break;
 		default:
 			snd_printd(KERN_ERR "invalid quirk type %d\n", quirk->type);
 			err = -ENXIO;