CONFIG_BOARD_ATSTK1003 is not available for thedefaultarchitecture x86.
Result is shown for architecture avr32
default or selected kernelversion does not have config value CONFIG_BOARD_ATSTK1003.
Result is shown for kernelversion 6.5.1

ATSTK1003

modulename: atstk1003.ko

configname: CONFIG_BOARD_ATSTK1003

ATSTK1000 CPU daughterboard type
└─>ATSTK1003
In linux kernel since version 2.6.25 (release Date: 2008-04-16)  
source code:
arch/avr32/boards/atstk1000/atstk1003.c