CONFIG_MACH_UC7112LX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

MOXA UC-7112-LX

modulename: moxart.ko

configname: CONFIG_MACH_UC7112LX

Linux Kernel Configuration
└─>MOXA ART SoC
└─>MOXA UC-7112-LX
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Say Y here if you intend to run this kernel on a MOXA
UC-7112-LX embedded computer.

source code:
arch/arm/mach-moxart/moxart.c