ASoC: generic: use asoc_substream_to_rtd()

Now we can use asoc_substream_to_rtd() macro,
let's use it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87zh7vyoex.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/generic/simple-card-utils.c

@@ -193,7 +193,7 @@ EXPORT_SYMBOL_GPL(asoc_simple_parse_clk);
 
 int asoc_simple_startup(struct snd_pcm_substream *substream)
 {
-	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(rtd->card);
 	struct simple_dai_props *dai_props = simple_priv_to_props(priv, rtd->num);
 	int ret;
@@ -212,7 +212,7 @@ EXPORT_SYMBOL_GPL(asoc_simple_startup);
 
 void asoc_simple_shutdown(struct snd_pcm_substream *substream)
 {
-	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
 	struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(rtd->card);
@@ -248,7 +248,7 @@ static int asoc_simple_set_clk_rate(struct asoc_simple_dai *simple_dai,
 int asoc_simple_hw_params(struct snd_pcm_substream *substream,
 			  struct snd_pcm_hw_params *params)
 {
-	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
 	struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(rtd->card);