ASoC: Make DAPM power sequence lists local variables

They are now only accessed within dapm_power_widgets() so can be local
to that function.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/soc.h

@@ -369,8 +369,6 @@ struct snd_soc_codec {
 	enum snd_soc_bias_level bias_level;
 	enum snd_soc_bias_level suspend_bias_level;
 	struct delayed_work delayed_work;
-	struct list_head up_list;
-	struct list_head down_list;
 
 	/* codec DAI's */
 	struct snd_soc_dai *dai;