ALSA: pcm: Embed struct device

Like previous patches, at this time we embed the struct device into
PCM object.  However, this needs a bit more caution: struct snd_pcm
doesn't own one device but two, for both playback and capture!  Thus
not struct snd_pcm but struct snd_pcm_str object contains the device.

Along with this change, pcm->dev field is dropped for avoiding
confusion.  It was meant to point to a non-standard parent.  But,
since now we can touch each struct device directly, we can manipulate
the parent field easily there, too.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index b429b73..735bd0c 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -449,6 +449,7 @@
 #endif
 #endif
 	struct snd_kcontrol *chmap_kctl; /* channel-mapping controls */
+	struct device dev;
 };
 
 struct snd_pcm {
@@ -465,7 +466,6 @@
 	wait_queue_head_t open_wait;
 	void *private_data;
 	void (*private_free) (struct snd_pcm *pcm);
-	struct device *dev; /* actual hw device this belongs to */
 	bool internal; /* pcm is for internal use only */
 	bool nonatomic; /* whole PCM operations are in non-atomic context */
 #if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)