watchdog: iTCO: Drop driver-internal locking

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 f4e9c82f64b5 ("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>