File _servicedata of Package ipxe

<servicedata>
  <service name="tar_scm">
    <param name="url">https://github.com/ipxe/ipxe.git</param>
    <param name="changesrevision">be3a78eaf804a2c437aa055d5c1e2f4a1310a0c1</param>
  </service>
</servicedata>