default or selected kernelversion does not have config value CONFIG_AU1000_SERIAL_CONSOLE.
Result is shown for kernelversion 5.15.113
Enable Au1000 serial console
configname: CONFIG_AU1000_SERIAL_CONSOLE
Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Enable Au1000 serial console
In linux kernel since version 2.6.20 (release Date: 2007-02-04)
If you have an Alchemy AU1000 processor (MIPS based) and you want
to use a console on a serial port, say Y. Otherwise, say N.
to use a console on a serial port, say Y. Otherwise, say N.