ALSA: fireworks: Add MIDI interface

This commit adds a functionality to capture/playback MIDI messages.

When no AMDTP streams are running, this driver starts AMDTP stream for MIDI
stream at current sampling rate.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/fireworks/fireworks.c

@@ -226,6 +226,12 @@ efw_probe(struct fw_unit *unit,
 
 	snd_efw_proc_init(efw);
 
+	if (efw->midi_out_ports || efw->midi_in_ports) {
+		err = snd_efw_create_midi_devices(efw);
+		if (err < 0)
+			goto error;
+	}
+
 	err = snd_efw_stream_init_duplex(efw);
 	if (err < 0)
 		goto error;