CONFIG_I8259 (not configurable)

modulename: irq-i8259.ko

configname: CONFIG_I8259

Linux Kernel Configuration
└─>Device Drivers
└─>IRQ chip support
└─>I8259
In linux kernel since version 2.6.12  
source code:
drivers/irqchip/irq-i8259.c
selects
CONFIG_IRQ_DOMAIN

is depended by
CONFIG_TOSHIBA_FPCIB0