watchdog: booke_wdt: Use infrastructure to check timeout limits

The watchdog infrastructure checks the maximum timeout for us.
Use it.

Signed-off-by: Guenter Roeck <[e-mail]>
Signed-off-by: Wim Van Sebroeck <[e-mail]>

drivers/watchdog/booke_wdt.c

···
 static int booke_wdt_set_timeout(struct watchdog_device *wdt_dev,
 				 unsigned int timeout)
 {
-	if (timeout > MAX_WDT_TIMEOUT)
-		return -EINVAL;
 	wdt_dev->timeout = timeout;
 	booke_wdt_set(wdt_dev);
 
···
 	.info = &booke_wdt_info,
 	.ops = &booke_wdt_ops,
 	.min_timeout = 1,
-	.max_timeout = 0xFFFF
 };
 
 static void __exit booke_wdt_exit(void)
···
 	booke_wdt_set_timeout(&booke_wdt_dev,
 			      period_to_sec(booke_wdt_period));
 	watchdog_set_nowayout(&booke_wdt_dev, nowayout);
+	booke_wdt_dev.max_timeout = MAX_WDT_TIMEOUT;
 	if (booke_wdt_enabled)
 		booke_wdt_start(&booke_wdt_dev);