serial: 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
index fe48a0c..440a962 100644
--- a/drivers/tty/serial/serial_txx9.c
+++ b/drivers/tty/serial/serial_txx9.c
@@ -1097,7 +1097,7 @@
  */
 static int serial_txx9_probe(struct platform_device *dev)
 {
-	struct uart_port *p = dev->dev.platform_data;
+	struct uart_port *p = dev_get_platdata(&dev->dev);
 	struct uart_port port;
 	int ret, i;