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

Kaen board

configname: CONFIG_MACH_KAEN

Linux Kernel Configuration
└─>Kaen board
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  
Support for the Kaen version of Seaboard