gpio: gpio-mm: Remove unnecessary driver_data set

Setting driver_data was necessary to access private data in the
gpiomm_remove function. Now that the gpiomm_remove function is gone,
driver_data is no longer used. This patch removes the relevant code.
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-gpio-mm.c

@@ -261,8 +261,6 @@ static int gpiomm_probe(struct device *dev, unsigned int id)
 
 	spin_lock_init(&gpiommgpio->lock);
 
-	dev_set_drvdata(dev, gpiommgpio);
-
 	err = devm_gpiochip_add_data(dev, &gpiommgpio->chip, gpiommgpio);
 	if (err) {
 		dev_err(dev, "GPIO registering failed (%d)\n", err);