hw/intc/arm_gicv3: Introduce redist-region-count array property

hw/intc/arm_gicv3: Introduce redist-region-count array property

To prepare for multiple redistributor regions, we introduce
an array of uint32_t properties that stores the redistributor
count of each redistributor region.

Non accelerated VGICv3 only supports a single redistributor region.
The capacity of all redist regions is checked against the number of
vcpus.

Machvirt is updated to set those properties, ie. a single
redistributor region with count set to the number of vcpus
capped by 123.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-id: 1529072910-16156-4-git-send-email-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>