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-omap.c b/drivers/gpio/gpio-omap.c
index dfeb3a3..867efe5 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -1100,7 +1100,7 @@
 
 	match = of_match_device(of_match_ptr(omap_gpio_match), dev);
 
-	pdata = match ? match->data : dev->platform_data;
+	pdata = match ? match->data : dev_get_platdata(dev);
 	if (!pdata)
 		return -EINVAL;