spi: cadence: 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/20190904135918.25352-9-yuehaibing@huawei.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-cadence.c

@@ -474,7 +474,6 @@ static int cdns_spi_probe(struct platform_device *pdev)
 	int ret = 0, irq;
 	struct spi_master *master;
 	struct cdns_spi *xspi;
-	struct resource *res;
 	u32 num_cs;
 
 	master = spi_alloc_master(&pdev->dev, sizeof(*xspi));
@@ -485,8 +484,7 @@ static int cdns_spi_probe(struct platform_device *pdev)
 	master->dev.of_node = pdev->dev.of_node;
 	platform_set_drvdata(pdev, master);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	xspi->regs = devm_ioremap_resource(&pdev->dev, res);
+	xspi->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(xspi->regs)) {
 		ret = PTR_ERR(xspi->regs);
 		goto remove_master;