tests/data: introduce "uefi-boot-images" with the "bios-tables-test" ISOs

Add UEFI-bootable qcow2-compressed ISO images built from:

  tests/uefi-test-tools/UefiTestToolsPkg/BiosTablesTest

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: Shannon Zhao <shannon.zhaosl@gmail.com>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190204160325.4914-6-lersek@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>