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-zynq.c b/drivers/gpio/gpio-zynq.c
index b3cc948..75ee877 100644
--- a/drivers/gpio/gpio-zynq.c
+++ b/drivers/gpio/gpio-zynq.c
@@ -562,7 +562,7 @@ static void zynq_gpio_handle_bank_irq(struct zynq_gpio *gpio,
 				      unsigned long pending)
 {
 	unsigned int bank_offset = gpio->p_data->bank_min[bank_num];
-	struct irq_domain *irqdomain = gpio->chip.irqdomain;
+	struct irq_domain *irqdomain = gpio->chip.irq.domain;
 	int offset;
 
 	if (!pending)