CONFIG_MACH_AT91SAM9G45EKES is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_MACH_AT91SAM9G45EKES.
Result is shown for kernelversion 5.4.229

Atmel AT91SAM9G45-EKES Evaluation Kit

modulename: board-sam9m10g45ek.ko

configname: CONFIG_MACH_AT91SAM9G45EKES

Linux Kernel Configuration
└─>Atmel AT91 System-on-Chip
└─>Atmel AT91SAM9G45-EKES Evaluation Kit
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
Select this if you are using Atmel's AT91SAM9G45-EKES Evaluation Kit.
"ES" at the end of the name means that this board is an
Engineering Sample.

source code: