ALSA: oxfw: Add proc interface for debugging purpose

This commit adds proc interface to get information about stream
formation. This commit also adds snd_oxfw_stream_get_current_formation()
to get current stream formation.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/oxfw/oxfw.h

@@ -18,6 +18,7 @@
 #include <sound/initval.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
+#include <sound/info.h>
 
 #include "../lib.h"
 #include "../fcp.h"
@@ -108,3 +109,5 @@ int snd_oxfw_stream_discover(struct snd_oxfw *oxfw);
 int snd_oxfw_create_pcm(struct snd_oxfw *oxfw);
 
 int snd_oxfw_create_mixer(struct snd_oxfw *oxfw);
+
+void snd_oxfw_proc_init(struct snd_oxfw *oxfw);