CONFIG_MACH_KOTA2 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

KOTA2 board

modulename: board-kota2.ko

configname: CONFIG_MACH_KOTA2

Linux Kernel Configuration
└─>KOTA2 board
In linux kernel since version 3.1 (release Date: 2011-10-24)  
source code:
arch/arm/mach-shmobile/board-kota2.c