ALSA: compress: Embed struct device

Like previous patches, this one embeds the struct device into struct
snd_compr.  As the dev field wasn't used beforehand, it's reused as
the new device struct.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
index 396e8f7..1d0593b 100644
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -134,7 +134,7 @@
 /**
  * struct snd_compr: Compressed device
  * @name: DSP device name
- * @dev: Device pointer
+ * @dev: associated device instance
  * @ops: pointer to DSP callbacks
  * @private_data: pointer to DSP pvt data
  * @card: sound card pointer
@@ -144,7 +144,7 @@
  */
 struct snd_compr {
 	const char *name;
-	struct device *dev;
+	struct device dev;
 	struct snd_compr_ops *ops;
 	void *private_data;
 	struct snd_card *card;