ASoC: dapm: Staticise dapm_mark_dirty()

The function is not called outside soc-dapm.c so there is no need for it
to be exported.
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/soc-dapm.h

@@ -471,7 +471,6 @@ int snd_soc_dapm_ignore_suspend(struct snd_soc_dapm_context *dapm,
 void snd_soc_dapm_auto_nc_codec_pins(struct snd_soc_codec *codec);
 
 /* Mostly internal - should not normally be used */
-void dapm_mark_dirty(struct snd_soc_dapm_widget *w, const char *reason);
 void dapm_mark_io_dirty(struct snd_soc_dapm_context *dapm);
 
 /* dapm path query */

sound/soc/soc-dapm.c

@@ -146,7 +146,7 @@ static bool dapm_dirty_widget(struct snd_soc_dapm_widget *w)
 	return !list_empty(&w->dirty);
 }
 
-void dapm_mark_dirty(struct snd_soc_dapm_widget *w, const char *reason)
+static void dapm_mark_dirty(struct snd_soc_dapm_widget *w, const char *reason)
 {
 	if (!dapm_dirty_widget(w)) {
 		dev_vdbg(w->dapm->dev, "Marking %s dirty due to %s\n",
@@ -154,7 +154,6 @@ void dapm_mark_dirty(struct snd_soc_dapm_widget *w, const char *reason)
 		list_add_tail(&w->dirty, &w->dapm->card->dapm_dirty);
 	}
 }
-EXPORT_SYMBOL_GPL(dapm_mark_dirty);
 
 void dapm_mark_io_dirty(struct snd_soc_dapm_context *dapm)
 {