CONFIG_ARCH_SA1100 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

SA1100-based

modulename: gpio-sa1100.ko

configname: CONFIG_ARCH_SA1100

ARM system type
└─>SA1100-based
In linux kernel since version 2.6.12  
Support for StrongARM 11x0 based boards.

source code:
drivers/gpio/gpio-sa1100.c