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/mpsc.c b/drivers/tty/serial/mpsc.c
index bc24f49..fba5257 100644
--- a/drivers/tty/serial/mpsc.c
+++ b/drivers/tty/serial/mpsc.c
@@ -1884,7 +1884,7 @@
 	if (dev->id == 0) {
 		if (!(rc = mpsc_shared_map_regs(dev))) {
 			pdata = (struct mpsc_shared_pdata *)
-				dev->dev.platform_data;
+				dev_get_platdata(&dev->dev);
 
 			mpsc_shared_regs.MPSC_MRR_m = pdata->mrr_val;
 			mpsc_shared_regs.MPSC_RCRR_m= pdata->rcrr_val;
@@ -2025,7 +2025,7 @@
 {
 	struct mpsc_pdata	*pdata;
 
-	pdata = (struct mpsc_pdata *)pd->dev.platform_data;
+	pdata = (struct mpsc_pdata *)dev_get_platdata(&pd->dev);
 
 	pi->port.uartclk = pdata->brg_clk_freq;
 	pi->port.iotype = UPIO_MEM;