Enable Advantech Embedded Controller Watchdog support

The driver is configured by CONFIG_ADVANTECH_EC_WDT. This kind of watchdog is present on industrial Advantech computers like ECU-579 1.

Sadly, the driver's KConfig has a dependency bug were it can be compiled into a non-operational state. Backport the upstreamed fix (6eb28a38f6478)2.

Note: This enables ISA_BUS_API which is disabled in current versions.

Closes: #1051449