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>

sound/firewire/Kconfig

@@ -123,6 +123,7 @@ config SND_BEBOB
 config SND_FIREWIRE_DIGI00X
 	tristate "Digidesign Digi 002/003 family support"
 	select SND_FIREWIRE_LIB
+	select SND_HWDEP
 	help
 	 Say Y here to include support for Digidesign Digi 002/003 family.
 	  * Digi 002 Console