gpio: rcar: set IRQ chip parent_device

This enables Runtime PM handling for interrupts.

By setting the parent_device in struct irq_chip genirq will call the
pm_runtime_get/put APIs when an IRQ is requested/freed.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-rcar.c

@@ -460,6 +460,7 @@ static int gpio_rcar_probe(struct platform_device *pdev)
 
 	irq_chip = &p->irq_chip;
 	irq_chip->name = name;
+	irq_chip->parent_device = dev;
 	irq_chip->irq_mask = gpio_rcar_irq_disable;
 	irq_chip->irq_unmask = gpio_rcar_irq_enable;
 	irq_chip->irq_set_type = gpio_rcar_irq_set_type;