CONFIG_SOC_AT91SAM9N12 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
AT91SAM9N12 family
modulename: at91sam9n12.ko
configname: CONFIG_SOC_AT91SAM9N12
Linux Kernel Configuration
└─>Atmel AT91 System-on-Chip
└─>AT91SAM9N12 family
In linux kernel since version 3.1 (release Date: 2011-10-24)
Select this if you are using Atmel's AT91SAM9N12 SoC.