irqchip: crossbar: Convert dra7 crossbar to stacked domains

irqchip: crossbar: Convert dra7 crossbar to stacked domains

Support for the TI crossbar used on the DRA7 family of chips
is implemented as an ugly hack on the side of the GIC.

Converting it to stacked domains makes it slightly more
palatable, as it results in a cleanup.

Unfortunately, as the DT bindings failed to acknowledge the
fact that this is actually yet another interrupt controller
(the third, actually), we have yet another breakage. Oh well.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1426088629-15377-3-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>