ASoC: ak4613: add missing mutex_lock()

We need to use mutex_lock() for priv->cnt / priv->iface,
but we are missing it at ak4613_dai_startup().
This patch adds missing mutex_lock() for it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87fsmsp9m7.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/ak4613.c

@@ -304,7 +304,9 @@ static int ak4613_dai_startup(struct snd_pcm_substream *substream,
 	struct snd_soc_component *component = dai->component;
 	struct ak4613_priv *priv = snd_soc_component_get_drvdata(component);
 
+	mutex_lock(&priv->lock);
 	priv->cnt++;
+	mutex_unlock(&priv->lock);
 
 	ak4613_hw_constraints(priv, substream->runtime);