irqchip: GICv3: ITS: tables allocators

The interrupt translation is driven by a set of tables (device,
ITT, and collection) to be in the end delivered to a CPU. Also,
the redistributors rely on a couple of tables (configuration, and
pending) to deliver the interrupts to the CPUs.

This patch adds the required allocators for these tables.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1416839720-18400-8-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>