serial: bfin_5xx: add missing spin_lock init

The Blackfin serial driver never initialized the spin_lock that is part of
the serial core structure, but we never noticed because spin_lock's are
rarely enabled on UP systems.  Yeah lockdep and friends.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/serial/bfin_5xx.c

@@ -1110,6 +1110,7 @@ static void __init bfin_serial_init_ports(void)
 	bfin_serial_hw_init();
 
 	for (i = 0; i < nr_active_ports; i++) {
+		spin_lock_init(&bfin_serial_ports[i].port.lock);
 		bfin_serial_ports[i].port.uartclk   = get_sclk();
 		bfin_serial_ports[i].port.fifosize  = BFIN_UART_TX_FIFO_SIZE;
 		bfin_serial_ports[i].port.ops       = &bfin_serial_pops;