CONFIG_BOARD_ATNGW100 is not available for thedefaultarchitecture x86.
Result is shown for architecture avr32
default or selected kernelversion does not have config value CONFIG_BOARD_ATNGW100.
Result is shown for kernelversion 5.4.159

ATNGW100 Network Gateway

configname: CONFIG_BOARD_ATNGW100

AVR32 board type
└─>ATNGW100 Network Gateway
In linux kernel since version 2.6.22 (release Date: 2007-07-08)