gpio: Move irqdomain into 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>
diff --git a/drivers/gpio/gpio-adnp.c b/drivers/gpio/gpio-adnp.c
index 7f475ee..44c0990 100644
--- a/drivers/gpio/gpio-adnp.c
+++ b/drivers/gpio/gpio-adnp.c
@@ -320,7 +320,7 @@ static irqreturn_t adnp_irq(int irq, void *data)
 
 		for_each_set_bit(bit, &pending, 8) {
 			unsigned int child_irq;
-			child_irq = irq_find_mapping(adnp->gpio.irqdomain,
+			child_irq = irq_find_mapping(adnp->gpio.irq.domain,
 						     base + bit);
 			handle_nested_irq(child_irq);
 		}