default or selected kernelversion does not have config value CONFIG_SERIAL_BFIN_UART0.
Result is shown for kernelversion 6.7-rc3

Enable UART0

configname: CONFIG_SERIAL_BFIN_UART0

Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Serial drivers
└─>Enable UART0
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
Enable UART0