default or selected kernelversion does not have config value CONFIG_B43_NPHY.
Result is shown for kernelversion 5.4.69

Pre IEEE 802.11n support (BROKEN)

configname: CONFIG_B43_NPHY

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wireless LAN
└─>Pre IEEE 802.11n support (BROKEN)
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
Support for the IEEE 802.11n draft.

THIS IS BROKEN AND DOES NOT WORK YET.

SAY N.

depends
CONFIG_B43
CONFIG_BROKEN
CONFIG_EXPERIMENTAL
CONFIG_NETDEVICES
CONFIG_WLAN