gpio: mxc: 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>
diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c
index c1a1e00..3abea3f 100644
--- a/drivers/gpio/gpio-mxc.c
+++ b/drivers/gpio/gpio-mxc.c
@@ -471,7 +471,7 @@ static int mxc_gpio_probe(struct platform_device *pdev)
 	if (err)
 		goto out_bgio;
 
-	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_bgio;
@@ -481,7 +481,7 @@ static int mxc_gpio_probe(struct platform_device *pdev)
 					     &irq_domain_simple_ops, NULL);
 	if (!port->domain) {
 		err = -ENODEV;
-		goto out_irqdesc_free;
+		goto out_bgio;
 	}
 
 	/* gpio-mxc can be a generic irq chip */
@@ -495,8 +495,6 @@ static int mxc_gpio_probe(struct platform_device *pdev)
 
 out_irqdomain_remove:
 	irq_domain_remove(port->domain);
-out_irqdesc_free:
-	irq_free_descs(irq_base, 32);
 out_bgio:
 	dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, err);
 	return err;