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/pinctrl/spear/pinctrl-plgpio.c b/drivers/pinctrl/spear/pinctrl-plgpio.c
index cf6d68c..72ae6bc 100644
--- a/drivers/pinctrl/spear/pinctrl-plgpio.c
+++ b/drivers/pinctrl/spear/pinctrl-plgpio.c
@@ -401,7 +401,7 @@ static void plgpio_irq_handler(struct irq_desc *desc)
 			/* get correct irq line number */
 			pin = i * MAX_GPIO_PER_REG + pin;
 			generic_handle_irq(
-				irq_find_mapping(gc->irqdomain, pin));
+				irq_find_mapping(gc->irq.domain, pin));
 		}
 	}
 	chained_irq_exit(irqchip, desc);