powerpc/mpsc: Set the port device in the mpsc serial driver

The mpsc serial driver needx to set the port's device tree element
to register properly.
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/serial/mpsc.c

@@ -2071,6 +2071,7 @@ static int mpsc_drv_probe(struct platform_device *dev)
 
 		if (!(rc = mpsc_drv_map_regs(pi, dev))) {
 			mpsc_drv_get_platform_data(pi, dev, dev->id);
+			pi->port.dev = &dev->dev;
 
 			if (!(rc = mpsc_make_ready(pi))) {
 				spin_lock_init(&pi->tx_lock);