gpio: mxs: use devm_irq_alloc_descs()

This driver never frees the interrupt descriptors it allocates. Fix
it by using the resource managed version of irq_alloc_descs().
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mxs.c

@@ -328,7 +328,7 @@ static int mxs_gpio_probe(struct platform_device *pdev)
 	/* clear address has to be used to clear IRQSTAT bits */
 	writel(~0U, port->base + PINCTRL_IRQSTAT(port) + MXS_CLR);
 
-	irq_base = irq_alloc_descs(-1, 0, 32, numa_node_id());
+	irq_base = devm_irq_alloc_descs(&pdev->dev, -1, 0, 32, numa_node_id());
 	if (irq_base < 0) {
 		err = irq_base;
 		goto out_iounmap;
@@ -338,7 +338,7 @@ static int mxs_gpio_probe(struct platform_device *pdev)
 					     &irq_domain_simple_ops, NULL);
 	if (!port->domain) {
 		err = -ENODEV;
-		goto out_irqdesc_free;
+		goto out_iounmap;
 	}
 
 	/* gpio-mxs can be a generic irq chip */
@@ -370,8 +370,6 @@ static int mxs_gpio_probe(struct platform_device *pdev)
 
 out_irqdomain_remove:
 	irq_domain_remove(port->domain);
-out_irqdesc_free:
-	irq_free_descs(irq_base, 32);
 out_iounmap:
 	iounmap(port->base);
 	return err;