irqchip: gicv3-its: Allocate enough memory for the full range of DeviceID

irqchip: gicv3-its: Allocate enough memory for the full range of DeviceID

The ITS table allocator is only allocating a single page per table.
This works fine for most things, but leads to silent lack of
interrupt delivery if we end-up with a device that has an ID that is
out of the range defined by a single page of memory. Even worse, depending
on the page size, behaviour changes, which is not a very good experience.

A solution is actually to allocate memory for the full range of ID that
the ITS supports. A massive waste memory wise, but at least a safe bet.

Tested on a Phytium SoC.

Tested-by: Chen Baozi <chenbaozi@kylinos.com.cn>
Acked-by: Chen Baozi <chenbaozi@kylinos.com.cn>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>