gpio: dwapb: avoid error message for optional IRQ

platform_get_irq() will generate an error message if the requested IRQ
is not present. Use platform_get_irq_optional() to avoid the error message
being generated.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20200519131233.59032-2-andriy.shevchenko@linux.intel.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-dwapb.c

@@ -549,7 +549,7 @@ static void dwapb_get_irq(struct device *dev, struct fwnode_handle *fwnode,
 		if (np)
 			pp->irq[j] = of_irq_get(np, j);
 		else if (has_acpi_companion(dev))
-			pp->irq[j] = platform_get_irq(to_platform_device(dev), j);
+			pp->irq[j] = platform_get_irq_optional(to_platform_device(dev), j);
 
 		if (pp->irq[j] >= 0)
 			pp->has_irq = true;