CONFIG_ARCH_SA1100 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARCH_SA1100.
Result is shown for kernelversion 6.9.9

SA11x0 Implementations

modulename: irq-sa11x0.ko

and/or

gpio-sa1100.ko

configname: CONFIG_ARCH_SA1100

Linux Kernel Configuration
└─>SA11x0 Implementations
In linux kernel since version 2.6.12  
Support for StrongARM 11x0 based boards.

source code:
drivers/irqchip/irq-sa11x0.c