default or selected kernelversion does not have config value CONFIG_ATLAS7_WATCHDOG.
Result is shown for kernelversion 6.9.9

CSRatlas7 watchdog

modulename: atlas7_wdt.ko

configname: CONFIG_ATLAS7_WATCHDOG

Linux Kernel Configuration
└─>Device Drivers
└─>Watchdog Timer Support
└─>CSRatlas7 watchdog
In linux kernel since version 4.1 (release Date: 2015-06-21)  
Say Y here to include Watchdog timer support for the watchdog
existing on the CSRatlas7 series platforms.

To compile this driver as a module, choose M here: the
module will be called atlas7_wdt.

source code:
depends
CONFIG_WATCHDOG
CONFIG_ARCH_ATLAS7 or CONFIG_COMPILE_TEST