watchdog: iTCO: Drop driver-internal locking

The locking code in the iTCO watchdog driver has been carried along from
before the watchdog core existed. The watchdog core protects calls into
drivers since commit f4e9c82f ("watchdog: Add Locking support"),
making driver-internal locking unnecessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Link: https://lore.kernel.org/r/20250517160936.3231017-1-linux@roeck-us.net


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>