Adds alternative ACPI table blob selection for testing
non default QEMU configurations. If blob file for test
variant is not present, fallback to default blob.
With this change implement testing with a coldplugged
bridge.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>