mailbox: xgene-slimpro: 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-xgene-slimpro.c

@@ -170,7 +170,6 @@ static const struct mbox_chan_ops slimpro_mbox_ops = {
 static int slimpro_mbox_probe(struct platform_device *pdev)
 {
 	struct slimpro_mbox *ctx;
-	struct resource *regs;
 	void __iomem *mb_base;
 	int rc;
 	int i;
@@ -181,8 +180,7 @@ static int slimpro_mbox_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, ctx);
 
-	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mb_base = devm_ioremap_resource(&pdev->dev, regs);
+	mb_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mb_base))
 		return PTR_ERR(mb_base);