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

Homebrew Serial Port Receiver

modulename: lirc_serial.ko

configname: CONFIG_LIRC_SERIAL

Linux Kernel Configuration
└─>Device Drivers
└─>Staging drivers
└─>Media staging drivers
└─>Linux Infrared Remote Control IR receiver/transmitter drivers
└─>Homebrew Serial Port Receiver
In linux kernel since version 2.6.36 (release Date: 2010-10-20)  
Driver for Homebrew Serial Port Receivers

source code: