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

Support Buglabs BUGBase platform

modulename: mach-bug.ko

configname: CONFIG_MACH_BUG

Linux Kernel Configuration
└─>Support Buglabs BUGBase platform
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  
Include support for BUGBase 1.3 platform. This includes specific
configurations for the board and its peripherals.

source code:
arch/arm/mach-imx/mach-bug.c