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-sta2x11.c b/drivers/gpio/gpio-sta2x11.c
index f43ab6a..f2fb12c 100644
--- a/drivers/gpio/gpio-sta2x11.c
+++ b/drivers/gpio/gpio-sta2x11.c
@@ -361,7 +361,7 @@
 	struct gsta_gpio *chip;
 	struct resource *res;
 
-	pdev = *(struct pci_dev **)(dev->dev.platform_data);
+	pdev = *(struct pci_dev **)dev_get_platdata(&dev->dev);
 	gpio_pdata = dev_get_platdata(&pdev->dev);
 
 	if (gpio_pdata == NULL)