gpio: drop devm_gpio_chip_match()

Commit 48207d75 ("gpio: drop devm_gpiochip_remove()") dropped the
last user of drop devm_gpio_chip_match(), causing a defined but not used
compilation warning. Fix it by removing the function.

Fixes: 48207d75 ("gpio: drop devm_gpiochip_remove()")
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib.c

@@ -1511,20 +1511,6 @@ static void devm_gpio_chip_release(struct device *dev, void *res)
 	gpiochip_remove(chip);
 }
 
-static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
-
-{
-	struct gpio_chip **r = res;
-
-	if (!r || !*r) {
-		WARN_ON(!r || !*r);
-		return 0;
-	}
-
-	return *r == data;
-}
-
-
 /**
  * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
  * @dev: pointer to the device that gpio_chip belongs to.