pinctrl: iproc: Use platform_get_irq_optional() to avoid error message

Use platform_get_irq_optional() instead of platform_get_irq() to avoid
below error message during probe:

[ 0.589121] iproc-gpio 66424800.gpio: IRQ index 0 not found

Signed-off-by: Rayagonda Kokatanur <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Chris Packham <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>

Author: rayagonda

drivers/pinctrl/bcm/pinctrl-iproc-gpio.c

@@ -849,7 +849,7 @@ static int iproc_gpio_probe(struct platform_device *pdev)
 							"gpio-ranges");
 
 	/* optional GPIO interrupt support */
-	irq = platform_get_irq(pdev, 0);
+	irq = platform_get_irq_optional(pdev, 0);
 	if (irq > 0) {
 		struct irq_chip *irqc;
 		struct gpio_irq_chip *girq;