gpio: ath79: use devm_platform_ioremap_resource()

There's no need to use the nocache variant of ioremap(). Switch to
using devm_platform_ioremap_resource().
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-ath79.c

@@ -226,7 +226,6 @@ static int ath79_gpio_probe(struct platform_device *pdev)
 	struct device_node *np = dev->of_node;
 	struct ath79_gpio_ctrl *ctrl;
 	struct gpio_irq_chip *girq;
-	struct resource *res;
 	u32 ath79_gpio_count;
 	bool oe_inverted;
 	int err;
@@ -256,12 +255,9 @@ static int ath79_gpio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -EINVAL;
-	ctrl->base = devm_ioremap_nocache(dev, res->start, resource_size(res));
-	if (!ctrl->base)
-		return -ENOMEM;
+	ctrl->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ctrl->base))
+		return PTR_ERR(ctrl->base);
 
 	raw_spin_lock_init(&ctrl->lock);
 	err = bgpio_init(&ctrl->gc, dev, 4,