gpio: Move irq_handler to struct gpio_irq_chip

In order to consolidate the multiple ways to associate an IRQ chip with
a GPIO chip, move more fields into the new struct gpio_irq_chip.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib.c

@@ -1646,7 +1646,7 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
 	 * category than their parents, so it won't report false recursion.
 	 */
 	irq_set_lockdep_class(irq, chip->lock_key);
-	irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq_handler);
+	irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
 	/* Chips that use nested thread handlers have them marked */
 	if (chip->irq_nested)
 		irq_set_nested_thread(irq, 1);
@@ -1820,7 +1820,7 @@ int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
 	}
 
 	gpiochip->irq.chip = irqchip;
-	gpiochip->irq_handler = handler;
+	gpiochip->irq.handler = handler;
 	gpiochip->irq_default_type = type;
 	gpiochip->to_irq = gpiochip_to_irq;
 	gpiochip->lock_key = lock_key;