CONFIG_MACH_STAMP9G20 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_MACH_STAMP9G20.
Result is shown for kernelversion 6.5.1

taskit Stamp9G20 CPU module

modulename: board-stamp9g20.ko

configname: CONFIG_MACH_STAMP9G20

Linux Kernel Configuration
└─>Atmel Non-DT world
└─>taskit Stamp9G20 CPU module
In linux kernel since version 2.6.35 (release Date: 2010-08-01)  
Select this if you are using taskit's Stamp9G20 CPU module on its
evaluation board.
<http://www.taskit.de/en/>

source code: