ASoC: imx-audmux: use devm_platform_ioremap_resource() to simplify code

Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20190727150738.54764-8-yuehaibing@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/imx-audmux.c

@@ -298,12 +298,10 @@ static int imx_audmux_parse_dt_defaults(struct platform_device *pdev,
 
 static int imx_audmux_probe(struct platform_device *pdev)
 {
-	struct resource *res;
 	const struct of_device_id *of_id =
 			of_match_device(imx_audmux_dt_ids, &pdev->dev);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	audmux_base = devm_ioremap_resource(&pdev->dev, res);
+	audmux_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(audmux_base))
 		return PTR_ERR(audmux_base);