default or selected kernelversion does not have config value CONFIG_21285_WATCHDOG.
Result is shown for kernelversion 6.0-rc7

DC21285 watchdog

modulename: wdt285.ko
configname: CONFIG_21285_WATCHDOG

Linux Kernel Configuration
└─> Device Drivers
└─> Watchdog Timer Support
└─> DC21285 watchdog

The Intel Footbridge chip contains a built-in watchdog circuit. Say Y
here if you wish to use this. Alternatively say M to compile the
driver as a module, which will be called wdt285.

This driver does not work on all machines. In particular, early CATS
boards have hardware problems that will cause the machine to simply
lock up if the watchdog fires.

"If in doubt, leave it out" - say N.

source code: