Due to the whole single instance based watchdog API we use static data
for the wm831x watchdog which means that if the system tries to register
a second one we end up trying to register the same miscdevice again,
corrupting the miscdevice list. Work around this by checking for duplicate
registrations until we get a watchdog core.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>