CONFIG_MACH_MITYOMAPL138 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Critical Link MityDSP-L138/MityARM-1808 SoM

modulename: board-mityomapl138.ko

configname: CONFIG_MACH_MITYOMAPL138

Linux Kernel Configuration
└─>TI DaVinci Implementations
└─>Critical Link MityDSP-L138/MityARM-1808 SoM
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
Say Y here to select the Critical Link MityDSP-L138/MityARM-1808
System on Module. Information on this SoM may be found at
http://www.mitydsp.com

source code: