default or selected kernelversion does not have config value CONFIG_RT2X00_LIB_RFKILL.
Result is shown for kernelversion 5.3.7

CONFIG_RT2X00_LIB_RFKILL (not configurable)

configname: CONFIG_RT2X00_LIB_RFKILL

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wireless LAN
└─>RT2X00_LIB_RFKILL
In linux kernel since version 2.6.24 (release Date: 2008-01-24)