gpio: tqmx86: really make IRQ optional

The tqmx86 MFD driver was passing IRQ 0 for "no IRQ" in the past. This
causes warnings with newer kernels.

Prepare the gpio-tqmx86 driver for the fixed MFD driver by handling a
missing IRQ properly.

Fixes: b868db94 ("gpio: tqmx86: Add GPIO from for this IO controller")
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpio-tqmx86.c

@@ -238,8 +238,8 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
 	struct resource *res;
 	int ret, irq;
 
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq < 0 && irq != -ENXIO)
 		return irq;
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
@@ -278,7 +278,7 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(&pdev->dev);
 
-	if (irq) {
+	if (irq > 0) {
 		struct irq_chip *irq_chip = &gpio->irq_chip;
 		u8 irq_status;