gpio: pca953x: suppress interrupts warning when not applicable

Don't warn about missing interrupts support when the parent interrupt is
not defined. Enabling interrupts support would not make it work anyway.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-pca953x.c

@@ -708,7 +708,7 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
 {
 	struct i2c_client *client = chip->client;
 
-	if (irq_base != -1 && (chip->driver_data & PCA_INT))
+	if (client->irq && irq_base != -1 && (chip->driver_data & PCA_INT))
 		dev_warn(&client->dev, "interrupt support not compiled in\n");
 
 	return 0;