ASoC: TSCS42xx: make functions pll_event and dac_event static

The functions pll_event and dac_event are local to the source and do
not need to be in global scope, so make them static.

Cleans up sparse warnings:
symbol 'pll_event' was not declared. Should it be static?
symbol 'dac_event' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Steven Eckhoff <steven.eckhoff.opensource@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/tscs42xx.c

@@ -355,7 +355,7 @@ static int dapm_micb_event(struct snd_soc_dapm_widget *w,
 	return 0;
 }
 
-int pll_event(struct snd_soc_dapm_widget *w,
+static int pll_event(struct snd_soc_dapm_widget *w,
 		     struct snd_kcontrol *kcontrol, int event)
 {
 	struct snd_soc_codec *codec = snd_soc_dapm_to_codec(w->dapm);
@@ -369,7 +369,7 @@ int pll_event(struct snd_soc_dapm_widget *w,
 	return ret;
 }
 
-int dac_event(struct snd_soc_dapm_widget *w,
+static int dac_event(struct snd_soc_dapm_widget *w,
 		     struct snd_kcontrol *kcontrol, int event)
 {
 	struct snd_soc_codec *codec = snd_soc_dapm_to_codec(w->dapm);