watchdog: max77620_wdt: fix potential build errors

watchdog: max77620_wdt: fix potential build errors

[ Upstream commit da9e3f4e30a53cd420cf1e6961c3b4110f0f21f0 ]

max77620_wdt uses watchdog core functions. Enable CONFIG_WATCHDOG_CORE
to fix potential build errors.

Signed-off-by: David Engraf <david.engraf@sysgo.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20191127084617.16937-1-david.engraf@sysgo.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>