watchdog: da9052: Fix invalid free of devm_ allocated data

It is not required to free devm_ allocated data. Since kref_put
needs a valid release function, da9052_wdt_release_resources()
is not deleted.

Fixes following warning.
drivers/watchdog/da9052_wdt.c:59:1-6: WARNING: invalid free of
devm_ allocated data
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/da9052_wdt.c

@@ -53,10 +53,6 @@ static const struct {
 
 static void da9052_wdt_release_resources(struct kref *r)
 {
-	struct da9052_wdt_data *driver_data =
-		container_of(r, struct da9052_wdt_data, kref);
-
-	kfree(driver_data);
 }
 
 static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,