ALSA: firewire-digi00x: add hwdep interface

This commit adds hwdep interface so as the other sound drivers for units
on IEEE 1394 bus have.

This interface is designed for mixer/control applications. By using this
interface, an application can get information about firewire node, can
lock/unlock kernel streaming and can get notification at starting/stopping
kernel streaming.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/uapi/sound/firewire.h b/include/uapi/sound/firewire.h
index 49122df..f67d228 100644
--- a/include/uapi/sound/firewire.h
+++ b/include/uapi/sound/firewire.h
@@ -56,6 +56,7 @@
 #define SNDRV_FIREWIRE_TYPE_FIREWORKS	2
 #define SNDRV_FIREWIRE_TYPE_BEBOB	3
 #define SNDRV_FIREWIRE_TYPE_OXFW	4
+#define SNDRV_FIREWIRE_TYPE_DIGI00X	5
 /* RME, MOTU, ... */
 
 struct snd_firewire_get_info {