dmaengine: sprd: Use devm_ioremap_resource() to map memory

Instead of checking the return value of platform_get_resource(), we can
use devm_ioremap_resource() which has the NULL pointer check and the
memory region requesting.
Suggested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/sprd-dma.c

@@ -807,10 +807,7 @@ static int sprd_dma_probe(struct platform_device *pdev)
 	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -EINVAL;
-	sdev->glb_base = devm_ioremap_nocache(&pdev->dev, res->start,
-					      resource_size(res));
+	sdev->glb_base = devm_ioremap_resource(&pdev->dev, res);
 	if (!sdev->glb_base)
 		return -ENOMEM;