gpio: 74xx-mmio: remove unneeded platform_set_drvdata() call

The platform_set_drvdata() was needed when the driver had an explicit
remove function.
That function got removed a while back, so we don't need to keep a pointer
(on 'dev->driver_data') for the private data of the driver anymore.
Signed-off-by: Alexandru Ardelean <alex@shruggie.ro>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-74xx-mmio.c

@@ -135,8 +135,6 @@ static int mmio_74xx_gpio_probe(struct platform_device *pdev)
 	priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
 	priv->gc.owner = THIS_MODULE;
 
-	platform_set_drvdata(pdev, priv);
-
 	return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
 }