The gpio-mpc8xxx driver requires IRQ domains but can be built
without them, resulting on a failure to build certain randconfigs
on ARM:
drivers/gpio/gpio-mpc8xxx.c: In function 'mpc8xxx_gpio_to_irq':
drivers/gpio/gpio-mpc8xxx.c:92:10: error: implicit declaration of function 'irq_create_mapping' [-Werror=implicit-function-declaration]
return irq_create_mapping(mpc8xxx_gc->irq, offset);
This selects IRQ_DOMAIN from the driver to ensure we can build it.