ASoC: Add helper function to check whether a CODEC is active

Instead of directly checking the 'active' field of the CODEC struct add a new
helper function that will return either true or false depending on whether the
CODEC is active. This will make the migration to the component level easier.

The patch also updates all CODEC drivers that check the active attribute to use
the new helper function.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

include/sound/soc.h

@@ -1172,6 +1172,11 @@ static inline bool snd_soc_volsw_is_stereo(struct soc_mixer_control *mc)
 	return 1;
 }
 
+static inline bool snd_soc_codec_is_active(struct snd_soc_codec *codec)
+{
+	return codec->active != 0;
+}
+
 int snd_soc_util_init(void);
 void snd_soc_util_exit(void);