ASoC: fsl: imx-spdif: cleanup platform which is using Generic DMA

If CPU is using soc-generic-dmaengine-pcm, Platform Component will be
same as CPU Component. In this case, we can use CPU dlc for Platform dlc.
This patch shares CPU dlc with Platform, and add comment.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Tested-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Link: https://lore.kernel.org/r/87a5z2f61w.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/imx-spdif.c

@@ -26,15 +26,19 @@ static int imx_spdif_audio_probe(struct platform_device *pdev)
 	}
 
 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	comp = devm_kzalloc(&pdev->dev, 3 * sizeof(*comp), GFP_KERNEL);
+	comp = devm_kzalloc(&pdev->dev, 2 * sizeof(*comp), GFP_KERNEL);
 	if (!data || !comp) {
 		ret = -ENOMEM;
 		goto end;
 	}
 
-	data->dai.cpus		= &comp[0];
+	/*
+	 * CPU == Platform
+	 * platform is using soc-generic-dmaengine-pcm
+	 */
+	data->dai.cpus		=
+	data->dai.platforms	= &comp[0];
 	data->dai.codecs	= &comp[1];
-	data->dai.platforms	= &comp[2];
 
 	data->dai.num_cpus	= 1;
 	data->dai.num_codecs	= 1;
@@ -45,7 +49,6 @@ static int imx_spdif_audio_probe(struct platform_device *pdev)
 	data->dai.codecs->dai_name = "snd-soc-dummy-dai";
 	data->dai.codecs->name = "snd-soc-dummy";
 	data->dai.cpus->of_node = spdif_np;
-	data->dai.platforms->of_node = spdif_np;
 	data->dai.playback_only = true;
 	data->dai.capture_only = true;