ASoC: Add indirection for CODEC private data

One of the features of the multi CODEC work is that it embeds a struct
device in the CODEC to provide diagnostics via a sysfs class rather than
via the device tree, at which point it's much better to use the struct
device private data rather than having two places to store it. Provide
an accessor function to allow this change to be made more easily, and
update all the CODEC drivers are updated.

To ensure use of the accessor the private data structure member is
renamed, meaning that if code developed with older an older core that
still uses private_data is merged it will fail to build.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/sound/soc/codecs/wm8776.c b/sound/soc/codecs/wm8776.c
index 44e7d9d..6946009 100644
--- a/sound/soc/codecs/wm8776.c
+++ b/sound/soc/codecs/wm8776.c
@@ -226,7 +226,7 @@
 			    struct snd_soc_dai *dai)
 {
 	struct snd_soc_codec *codec = dai->codec;
-	struct wm8776_priv *wm8776 = codec->private_data;
+	struct wm8776_priv *wm8776 = snd_soc_codec_get_drvdata(codec);
 	int iface_reg, iface;
 	int ratio_shift, master;
 	int i;
@@ -303,7 +303,7 @@
 			     int clk_id, unsigned int freq, int dir)
 {
 	struct snd_soc_codec *codec = dai->codec;
-	struct wm8776_priv *wm8776 = codec->private_data;
+	struct wm8776_priv *wm8776 = snd_soc_codec_get_drvdata(codec);
 
 	BUG_ON(dai->id >= ARRAY_SIZE(wm8776->sysclk));
 
@@ -490,7 +490,7 @@
 	INIT_LIST_HEAD(&codec->dapm_widgets);
 	INIT_LIST_HEAD(&codec->dapm_paths);
 
-	codec->private_data = wm8776;
+	snd_soc_codec_set_drvdata(codec, wm8776);
 	codec->name = "WM8776";
 	codec->owner = THIS_MODULE;
 	codec->bias_level = SND_SOC_BIAS_OFF;