pinctrl: ocelot: Fix interrupt parsing

In the blamed commit, it removes the duplicate of_node assignment in the
driver. But the driver uses this before calling into of_gpio_dev_init to
determine if it needs to assign an IRQ chip to the GPIO. The fixes
consists in using the platform_get_irq_optional

Fixes: 8a8d6bbe1d ("pinctrl: Get rid of duplicate of_node assignment in the drivers")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://lore.kernel.org/r/20220304144432.3397621-3-horatiu.vultur@microchip.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-ocelot.c

@@ -1851,8 +1851,8 @@ static int ocelot_gpiochip_register(struct platform_device *pdev,
 	gc->base = -1;
 	gc->label = "ocelot-gpio";
 
-	irq = irq_of_parse_and_map(gc->of_node, 0);
-	if (irq) {
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq > 0) {
 		girq = &gc->irq;
 		girq->chip = &ocelot_irqchip;
 		girq->parent_handler = ocelot_irq_handler;