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>
diff --git a/sound/soc/pxa/corgi.c b/sound/soc/pxa/corgi.c
index 97e9423..f451acd 100644
--- a/sound/soc/pxa/corgi.c
+++ b/sound/soc/pxa/corgi.c
@@ -100,8 +100,13 @@
 	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 */
 	corgi_ext_control(codec);
+
+	mutex_unlock(&codec->mutex);
+
 	return 0;
 }