kernelconfig_penguin
default or selected kernelversion does not have config value CONFIG_AU1000_SERIAL_CONSOLE.
Result is shown for kernelversion 2.6.20.9

Enable Au1000 serial console

configname: CONFIG_AU1000_SERIAL_CONSOLE

Linux Kernel Configuration
└─> Device Drivers
└─> Character devices
└─> Enable Au1000 serial console

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.