gpio: mc33880: use gpiochip data pointer

This makes the driver use the data pointer added to the gpio_chip
to store a pointer to the state container instead of relying on
container_of().
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mc33880.c

@@ -71,7 +71,7 @@ static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
 
 static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
 {
-	struct mc33880 *mc = container_of(chip, struct mc33880, chip);
+	struct mc33880 *mc = gpiochip_get_data(chip);
 
 	mutex_lock(&mc->lock);
 
@@ -135,7 +135,7 @@ static int mc33880_probe(struct spi_device *spi)
 		goto exit_destroy;
 	}
 
-	ret = gpiochip_add(&mc->chip);
+	ret = gpiochip_add_data(&mc->chip, mc);
 	if (ret)
 		goto exit_destroy;