CONFIG_ARCH_AT91SAM9G20 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARCH_AT91SAM9G20.
Result is shown for kernelversion 6.5.1

CONFIG_ARCH_AT91SAM9G20 (not configurable)

configname: CONFIG_ARCH_AT91SAM9G20

Linux Kernel Configuration
└─>Atmel Non-DT world
└─>ARCH_AT91SAM9G20
In linux kernel since version 2.6.27 (release Date: 2008-10-09)