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

CONFIG_CXL_LIB (not configurable)

configname: CONFIG_CXL_LIB

Linux Kernel Configuration
└─>Device Drivers
└─>Misc devices
└─>CXL_LIB
In linux kernel since version 4.2 (release Date: 2015-08-30)