dev-arm: Fix PCI node's interrupt-map property

dev-arm: Fix PCI node's interrupt-map property

The PCI host has an interrupt-map property which only works for a fixed
setup of parent/child interrupt/address cells, which currently overlaps
with GICv2.
We want to make this flexible, so that the interrupt-map doesn't break
if we change the interrupt/address-cells value, and the patch is aiming
in that direction.  This is also needed for GICv3 DTB autogeneration,
since it is using different values than GICv2.

Change-Id: If1c661ddcbc0c277c9d6b0e44a0fd3fe2427618c
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20052
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>