haven: irq: Support lending from other domains

Client drivers may lend IRQs with knowledge of only their GPIO interrupt
number, which would not directly have an underlying GIC hwirq. Thus,
tweak RM's understanding of IRQs to be aware of IRQ domains. Now, the
irq backed by GPIO will be translated to GIC domain.

Change-Id: I191d9e072b14f4501f5bbeb5d5263f50e0eef8c1
Signed-off-by: Elliot Berman <eberman@codeaurora.org>