watchdog: advantech_ec_wdt: fix Kconfig dependencies

This driver uses the WATCHDOG_CORE framework and ISA_BUS_API.
This commit has these dependencies correctly selected.

Signed-off-by: Florent CARLI <fcarli@gmail.com>
Co-authored-by: Yoann Congal <yoann.congal@smile.fr>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230721081347.52069-1-fcarli@gmail.com


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