ALSA: fireface: add hwdep interface

This commit adds hwdep interface so as the other drivers for audio and
music units on IEEE 1394 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/sound/firewire/Kconfig b/sound/firewire/Kconfig
index b75a822..70f02ee 100644
--- a/sound/firewire/Kconfig
+++ b/sound/firewire/Kconfig
@@ -155,6 +155,7 @@
 config SND_FIREFACE
 	tristate "RME Fireface series support"
 	select SND_FIREWIRE_LIB
+	select SND_HWDEP
 	help
 	 Say Y here to include support for RME fireface series.