gpio: use dev_get_platdata()

Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-mc33880.c b/drivers/gpio/gpio-mc33880.c
index 63a7a1b..3fd2caa 100644
--- a/drivers/gpio/gpio-mc33880.c
+++ b/drivers/gpio/gpio-mc33880.c
@@ -86,7 +86,7 @@
 	struct mc33880_platform_data *pdata;
 	int ret;
 
-	pdata = spi->dev.platform_data;
+	pdata = dev_get_platdata(&spi->dev);
 	if (!pdata || !pdata->base) {
 		dev_dbg(&spi->dev, "incorrect or missing platform data\n");
 		return -EINVAL;