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

drivers/watchdog/starfive-wdt.c

@@ -202,12 +202,14 @@ static u32 starfive_wdt_ticks_to_sec(struct starfive_wdt *wdt, u32 ticks)
 
 /* Write unlock-key to unlock. Write other value to lock. */
 static void starfive_wdt_unlock(struct starfive_wdt *wdt)
+	__acquires(&wdt->lock)
 {
 	spin_lock(&wdt->lock);
 	writel(wdt->variant->unlock_key, wdt->base + wdt->variant->unlock);
 }
 
 static void starfive_wdt_lock(struct starfive_wdt *wdt)
+	__releases(&wdt->lock)
 {
 	writel(~wdt->variant->unlock_key, wdt->base + wdt->variant->unlock);
 	spin_unlock(&wdt->lock);