ASoC: simple_card_utils.h: care NULL dai at asoc_simple_debug_dai()

props->xxx_dai might be NULL when DPCM.
This patch cares it for debug.

Fixes: commit 0580dde594 ("ASoC: simple-card-utils: add asoc_simple_debug_info()")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87o922gw4u.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/simple_card_utils.h

@@ -141,6 +141,10 @@ inline void asoc_simple_debug_dai(struct asoc_simple_priv *priv,
 {
 	struct device *dev = simple_priv_to_dev(priv);
 
+	/* dai might be NULL */
+	if (!dai)
+		return;
+
 	if (dai->name)
 		dev_dbg(dev, "%s dai name = %s\n",
 			name, dai->name);