ASoC: sun4i-i2s: Switch to devm for PCM register

Since the introduction of the driver, a new managed helper for the
dmaengine PCM registration has been created. Let's use it to simplify a bit
our probe and remove functions.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://lore.kernel.org/r/606d271187091e858e8c15e20555af0b79798fe1.1566242458.git-series.maxime.ripard@bootlin.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sunxi/sun4i-i2s.c

@@ -1154,7 +1154,7 @@ static int sun4i_i2s_probe(struct platform_device *pdev)
 		goto err_suspend;
 	}
 
-	ret = snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not register PCM\n");
 		goto err_suspend;
@@ -1183,8 +1183,6 @@ static int sun4i_i2s_remove(struct platform_device *pdev)
 {
 	struct sun4i_i2s *i2s = dev_get_drvdata(&pdev->dev);
 
-	snd_dmaengine_pcm_unregister(&pdev->dev);
-
 	pm_runtime_disable(&pdev->dev);
 	if (!pm_runtime_status_suspended(&pdev->dev))
 		sun4i_i2s_runtime_suspend(&pdev->dev);