default or selected kernelversion does not have config value CONFIG_BRCMISCAN.
Result is shown for kernelversion 5.15.31

Broadcom I-Scan (OBSOLETE)

configname: CONFIG_BRCMISCAN

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wireless LAN
└─>Broadcom I-Scan (OBSOLETE)
In linux kernel since version 3.7 (release Date: 2012-12-10)  
This option enables the I-Scan method. By default fullmac uses the
new E-Scan method which uses less memory in firmware and gives no
limitation on the number of scan results.