ALSA: firewire-motu: add skeleton for Mark of the unicorn (MOTU) FireWire series

This commit adds an new driver for MOTU FireWire series. In this commit,
this driver just creates/removes card instance according to bus event.
More functionalities will be added in following commits.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/firewire/Makefile b/sound/firewire/Makefile
index 0ee1fb1..9388ded6 100644
--- a/sound/firewire/Makefile
+++ b/sound/firewire/Makefile
@@ -13,3 +13,4 @@
 obj-$(CONFIG_SND_BEBOB) += bebob/
 obj-$(CONFIG_SND_FIREWIRE_DIGI00X) += digi00x/
 obj-$(CONFIG_SND_FIREWIRE_TASCAM) += tascam/
+obj-$(CONFIG_SND_FIREWIRE_MOTU) += motu/