ASoC: codecs: 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/871rl70yse.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt5677-spi.c

@@ -112,7 +112,7 @@ static int rt5677_spi_pcm_close(
 		struct snd_soc_component *component,
 		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_component *codec_component =
 			snd_soc_rtdcom_lookup(rtd, "rt5677");
 	struct rt5677_priv *rt5677 =
@@ -158,7 +158,7 @@ static int rt5677_spi_prepare(
 		struct snd_soc_component *component,
 		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_component *rt5677_component =
 			snd_soc_rtdcom_lookup(rtd, "rt5677");
 	struct rt5677_priv *rt5677 =