CONFIG_MACH_DEVKIT8000 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

DEVKIT8000 board

modulename: board-devkit8000.ko

configname: CONFIG_MACH_DEVKIT8000

Linux Kernel Configuration
└─>TI OMAP2/3/4 Specific Features
└─>DEVKIT8000 board
In linux kernel since version 2.6.34 (release Date: 2010-05-16)  
source code:
arch/arm/mach-omap2/board-devkit8000.c