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

CONFIG_VIDEO_BTCX (not configurable)

modulename: btcx-risc.ko

configname: CONFIG_VIDEO_BTCX

Linux Kernel Configuration
└─>Device Drivers
└─>Multimedia support
└─>VIDEO_BTCX
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
source code:
drivers/media/common//btcx-risc.c