CONFIG_ARCH_CDB89712 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CDB89712

modulename: cdb89712.ko

and/or

board-cdb89712.ko

configname: CONFIG_ARCH_CDB89712

Linux Kernel Configuration
└─>CLPS711X/EP721X Implementations
└─>CDB89712
In linux kernel since version 2.6.12  
This is an evaluation board from Cirrus for the CS89712 processor.
The board includes 2 serial ports, Ethernet, IRDA, and expansion
headers. It comes with 16 MB SDRAM and 8 MB flash ROM.

source code:
arch/arm/mach-clps711x/cdb89712.c
selects
CONFIG_ISA