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-ftgpio010.c b/drivers/gpio/gpio-ftgpio010.c
index e9386f8..b7896ba 100644
--- a/drivers/gpio/gpio-ftgpio010.c
+++ b/drivers/gpio/gpio-ftgpio010.c
@@ -149,7 +149,7 @@ static void ftgpio_gpio_irq_handler(struct irq_desc *desc)
 	stat = readl(g->base + GPIO_INT_STAT);
 	if (stat)
 		for_each_set_bit(offset, &stat, gc->ngpio)
-			generic_handle_irq(irq_find_mapping(gc->irqdomain,
+			generic_handle_irq(irq_find_mapping(gc->irq.domain,
 							    offset));
 
 	chained_irq_exit(irqchip, desc);