CONFIG_MACH_IM42xx is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

OpenGear IM42xx

modulename: board-og.ko

configname: CONFIG_MACH_IM42xx

Linux Kernel Configuration
└─>Kendin/Micrel KS8695 Implementations
└─>OpenGear IM42xx
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Say 'Y' here if you want your kernel to support the OpenGear
IM4216 or IM4248 Console Servers. See for
more details.

source code: