hw/arm/virt: Enable device memory cold/hot plug with ACPI boot

hw/arm/virt: Enable device memory cold/hot plug with ACPI boot

This initializes the GED device with base memory and irq, configures
ged memory hotplug event and builds the corresponding aml code. With
this, both hot and cold plug of device memory is enabled now for Guest
with ACPI boot. Memory cold plug support with Guest DT boot is not yet
supported.

As DSDT table gets changed by this, update bios-tables-test-allowed-diff.h
to avoid "make check" failure.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Message-Id: <20190918130633.4872-6-shameerali.kolothum.thodi@huawei.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>