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

Generic (aka Sharp Corgi) Backlight Driver

modulename: generic_bl.ko

configname: CONFIG_BACKLIGHT_GENERIC

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Backlight & LCD device support
└─>Generic (aka Sharp Corgi) Backlight Driver
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
Say y to enable the generic platform backlight driver previously
known as the Corgi backlight driver. If you have a Sharp Zaurus
SL-C7xx, SL-Cxx00 or SL-6000x say y.

source code: