ASoC: don't use rtd->codec on soc_dev_attr_is_visible()

rtd->codec will be removed soon.
checking rtd->num_codecs is enough
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-core.c

@@ -213,7 +213,7 @@ static umode_t soc_dev_attr_is_visible(struct kobject *kobj,
 
 	if (attr == &dev_attr_pmdown_time.attr)
 		return attr->mode; /* always visible */
-	return rtd->codec ? attr->mode : 0; /* enabled only with codec */
+	return rtd->num_codecs ? attr->mode : 0; /* enabled only with codec */
 }
 
 static const struct attribute_group soc_dapm_dev_group = {