ASoC: Remove codec field from snd_soc_dapm_widget

There are no more users of this field left so it can finally be removed.
New users should use snd_soc_dapm_to_codec(w->dapm);

The reason why it is removed is because it doesn't fit to well anymore in
the componentized ASoC hierarchy, where DAPM works on the snd_soc_component
level. And the alternative of snd_soc_dapm_to_codec(w->dapm) typically
generates the same amount of code, so there is really no reason to keep it.

For automatic conversion the following coccinelle semantic patch can be used:
// <smpl>
@@
struct snd_soc_dapm_widget *w;
@@
-w->codec
+snd_soc_dapm_to_codec(w->dapm)
// </smpl>
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

include/sound/soc-dapm.h

@@ -526,7 +526,6 @@ struct snd_soc_dapm_widget {
 	enum snd_soc_dapm_type id;
 	const char *name;		/* widget name */
 	const char *sname;	/* stream name */
-	struct snd_soc_codec *codec;
 	struct list_head list;
 	struct snd_soc_dapm_context *dapm;
 

sound/soc/soc-dapm.c

@@ -3130,8 +3130,6 @@ snd_soc_dapm_new_control(struct snd_soc_dapm_context *dapm,
 	}
 
 	w->dapm = dapm;
-	if (dapm->component)
-		w->codec = dapm->component->codec;
 	INIT_LIST_HEAD(&w->sources);
 	INIT_LIST_HEAD(&w->sinks);
 	INIT_LIST_HEAD(&w->list);