Add spin_locking to orion5x_wdt.c to prevent races.
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

This patch allows the use of the hardware watchdog in the
Marvell Orion series of ARM SoCs.
Signed-off-by: NSylver Bruneau <sylver.bruneau@googlemail.com>
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>