CONFIG_MACH_AT91SAM9M10G45EK is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Atmel AT91SAM9M10G45-EK Evaluation Kits

modulename: board-sam9m10g45ek.ko

configname: CONFIG_MACH_AT91SAM9M10G45EK

Linux Kernel Configuration
└─>Atmel AT91 System-on-Chip
└─>Atmel AT91SAM9M10G45-EK Evaluation Kits
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
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: