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

CONFIG_VIDEOBUF_GEN (not configurable)

modulename: videobuf-core.ko

configname: CONFIG_VIDEOBUF_GEN

Linux Kernel Configuration
└─>Device Drivers
└─>Multimedia support
└─>Video4Linux options
└─>VIDEOBUF_GEN
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
source code: