ALSA: compress: Add procfs info file for compressed nodes

This patch implements a procfs info file for compr nodes when
SND_VERBOSE_PROCFS is enabled. This is equivalent to what the PCM
core already does for pcm nodes.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
index fa1d055..85c4237 100644
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -152,6 +152,11 @@
 	unsigned int direction;
 	struct mutex lock;
 	int device;
+#ifdef CONFIG_SND_VERBOSE_PROCFS
+	char id[64];
+	struct snd_info_entry *proc_root;
+	struct snd_info_entry *proc_info_entry;
+#endif
 };
 
 /* compress device register APIs */