CONFIG_MACH_ARTPEC6 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Axis ARTPEC-6 ARM Cortex A9 Platform

modulename: board-artpec6.ko

and/or

clk-artpec6.ko

configname: CONFIG_MACH_ARTPEC6

Linux Kernel Configuration
└─>Axis Communications ARM based ARTPEC SoCs
└─>Axis ARTPEC-6 ARM Cortex A9 Platform
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Support for Axis ARTPEC-6 ARM Cortex A9 Platform

source code:
arch/arm/mach-artpec/board-artpec6.c