mailbox: sti: Make use of the helper function devm_platform_ioremap_resource()

Use the devm_platform_ioremap_resource() helper instead of
calling platform_get_resource() and devm_ioremap_resource()
separately
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

drivers/mailbox/mailbox-sti.c

@@ -408,7 +408,6 @@ static int sti_mbox_probe(struct platform_device *pdev)
 	struct sti_mbox_device *mdev;
 	struct device_node *np = pdev->dev.of_node;
 	struct mbox_chan *chans;
-	struct resource *res;
 	int irq;
 	int ret;
 
@@ -425,8 +424,7 @@ static int sti_mbox_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, mdev);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mdev->base = devm_ioremap_resource(&pdev->dev, res);
+	mdev->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mdev->base))
 		return PTR_ERR(mdev->base);