gpio: rcar: Use irqchip template

This makes the driver use the irqchip template to assign
properties to the gpio_irq_chip instead of using the
explicit call to gpiochip_irqchip_add().

The irqchip is instead added while adding the gpiochip.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Biju Das <biju.das@bp.renesas.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200722113141.243163-1-linus.walleij@linaro.org

drivers/gpio/gpio-rcar.c

@@ -438,6 +438,7 @@ static int gpio_rcar_probe(struct platform_device *pdev)
 	struct resource *irq;
 	struct gpio_chip *gpio_chip;
 	struct irq_chip *irq_chip;
+	struct gpio_irq_chip *girq;
 	struct device *dev = &pdev->dev;
 	const char *name = dev_name(dev);
 	unsigned int npins;
@@ -496,19 +497,21 @@ static int gpio_rcar_probe(struct platform_device *pdev)
 	irq_chip->irq_set_wake = gpio_rcar_irq_set_wake;
 	irq_chip->flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_MASK_ON_SUSPEND;
 
+	girq = &gpio_chip->irq;
+	girq->chip = irq_chip;
+	/* This will let us handle the parent IRQ in the driver */
+	girq->parent_handler = NULL;
+	girq->num_parents = 0;
+	girq->parents = NULL;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_level_irq;
+
 	ret = gpiochip_add_data(gpio_chip, p);
 	if (ret) {
 		dev_err(dev, "failed to add GPIO controller\n");
 		goto err0;
 	}
 
-	ret = gpiochip_irqchip_add(gpio_chip, irq_chip, 0, handle_level_irq,
-				   IRQ_TYPE_NONE);
-	if (ret) {
-		dev_err(dev, "cannot add irqchip\n");
-		goto err1;
-	}
-
 	p->irq_parent = irq->start;
 	if (devm_request_irq(dev, irq->start, gpio_rcar_irq_handler,
 			     IRQF_SHARED, name, p)) {