default or selected kernelversion does not have config value CONFIG_OF_SELFTEST.
Result is shown for kernelversion 6.5.1

Device Tree Runtime self tests

modulename: selftest.ko


Linux Kernel Configuration
└─>Device Drivers
└─>Device Tree and Open Firmware support
└─>Device Tree Runtime self tests
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This option builds in test cases for the device tree infrastructure
that are executed once at boot time, and the results dumped to the

If unsure, say N here, but this option is safe to enable.

source code: