default or selected kernelversion does not have config value CONFIG_ADX_WATCHDOG.
Result is shown for kernelversion 6.2.5

Avionic Design Xanthos watchdog

modulename: adx_wdt.ko

configname: CONFIG_ADX_WATCHDOG

Linux Kernel Configuration
└─>Device Drivers
└─>Watchdog Timer Support
└─>Avionic Design Xanthos watchdog
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
Say Y here if you want support for the watchdog timer on Avionic
Design Xanthos boards.

source code:
depends
CONFIG_ARCH_PXA_ADX
CONFIG_WATCHDOG