hw/intc/arm_gicv3_kvm: Get prepared to handle multiple redist regions

hw/intc/arm_gicv3_kvm: Get prepared to handle multiple redist regions

Let's check if KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION is supported.
If not, we check the number of redist region is equal to 1 and use the
legacy KVM_VGIC_V3_ADDR_TYPE_REDIST attribute. Otherwise we use
the new attribute and allow to register multiple regions to the
KVM device.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-id: 1529072910-16156-5-git-send-email-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>