irqchip: gic: Get rid of routable domain

The only user of the so called "routable domain" functionality
now being fixed, let's clean up the GIC.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1426088629-15377-5-git-send-email-marc.zyngier@arm.com


Signed-off-by: Jason Cooper <jason@lakedaemon.net>