hw/arm/virt: Check the VCPU PA range in TCG mode

We are about to allow the memory map to grow beyond 1TB and
potentially overshoot the VCPU AA64MMFR0.PARANGE.

In aarch64 mode and when highmem is set, let's check the VCPU
PA range is sufficient to address the highest GPA of the memory
map.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-id: 20190304101339.25970-10-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>