gpio: grgpio: Use devm_platform_ioremap_resource()

Use the new helper that wraps the calls to platform_get_resource()
and devm_ioremap_resource() together.

Signed-off-by: Enrico Weigelt, metux IT consult <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-grgpio.c

···
 	void  __iomem *regs;
 	struct gpio_chip *gc;
 	struct grgpio_priv *priv;
-	struct resource *res;
 	int err;
 	u32 prop;
 	s32 *irqmap;
···
 	if (!priv)
 		return -ENOMEM;
 
-	res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
-	regs = devm_ioremap_resource(&ofdev->dev, res);
+	regs = devm_platform_ioremap_resource(ofdev, 0);
 	if (IS_ERR(regs))
 		return PTR_ERR(regs);