watchdog: starfive: add lock annotations to fix context imbalances

Add the necessary __acquires() and __releases() to the functions
that take and release the wdt lock to avoid the following sparse
warnings:

drivers/watchdog/starfive-wdt.c:204:13: warning: context imbalance in 'starfive_wdt_unlock' - wrong count at exit
drivers/watchdog/starfive-wdt.c:212:9: warning: context imbalance in 'starfive_wdt_lock' - unexpected unlock

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20231122085118.177589-1-ben.dooks@codethink.co.uk


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