[POWERPC] mpc5200: Fix unterminated of_device_id table

If CONFIG_PPC_MPC5121 is not set, then the of_device_id table for the
mpc5200 serial driver will not get terminated with a NULL entry.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

drivers/serial/mpc52xx_uart.c

@@ -1221,8 +1221,8 @@ static struct of_device_id mpc52xx_uart_of_match[] = {
 #endif
 #ifdef CONFIG_PPC_MPC512x
 	{ .compatible = "fsl,mpc5121-psc-uart", .data = &mpc512x_psc_ops, },
-	{},
 #endif
+	{},
 };
 
 static int __devinit