ASoC: Lock the CODEC in PXA external jack controls

When doing anything with the system, especially DAPM, we need to hold the
CODEC mutex.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>

sound/soc/pxa/magician.c

@@ -72,9 +72,13 @@ static int magician_startup(struct snd_pcm_substream *substream)
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_codec *codec = rtd->codec;
 
+	mutex_lock(&codec->mutex);
+
 	/* check the jack status at stream startup */
 	magician_ext_control(codec);
 
+	mutex_unlock(&codec->mutex);
+
 	return 0;
 }