ASoC: wm8997: Replace w->codec snd_soc_dapm_to_codec(w->dapm)

The codec field of the snd_soc_widget struct is eventually going to be
removed, use snd_soc_dapm_to_codec(w->dapm) instead.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm8997.c

@@ -84,7 +84,7 @@ static const struct reg_default wm8997_sysclk_reva_patch[] = {
 static int wm8997_sysclk_ev(struct snd_soc_dapm_widget *w,
 			    struct snd_kcontrol *kcontrol, int event)
 {
-	struct snd_soc_codec *codec = w->codec;
+	struct snd_soc_codec *codec = snd_soc_dapm_to_codec(w->dapm);
 	struct arizona *arizona = dev_get_drvdata(codec->dev->parent);
 	struct regmap *regmap = arizona->regmap;
 	const struct reg_default *patch = NULL;