CONFIG_MACH_EUKREA_CPUIMX51 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Support Eukrea CPUIMX51 module

modulename: mach-cpuimx51.ko

configname: CONFIG_MACH_EUKREA_CPUIMX51

Linux Kernel Configuration
└─>Support Eukrea CPUIMX51 module
In linux kernel since version 2.6.36 (release Date: 2010-10-20)  
Include support for Eukrea CPUIMX51 platform. This includes
specific configurations for the module and its peripherals.

source code:
arch/arm/mach-imx/mach-cpuimx51.c