drivers/dma: don't check resource with devm_ioremap_resource

devm_ioremap_resource does sanity checks on the given resource. No need to
duplicate this in the driver.
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Stephen Warren <swarren@nvidia.com>

drivers/dma/tegra20-apb-dma.c

@@ -1273,11 +1273,6 @@ static int tegra_dma_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, tdma);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(&pdev->dev, "No mem resource for DMA\n");
-		return -EINVAL;
-	}
-
 	tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(tdma->base_addr))
 		return PTR_ERR(tdma->base_addr);