- Introduce the ability to use two instances
     of the same driver.
   - Impact: poller are expected to take a mandatory
     argument that has the type __po_hi_device_id

 * ocarina/src/backends/ocarina-backends-po_hi_c-activity.adb
 * ocarina/src/backends/ocarina-backends-c_tree-nutils.adb
   ocarina/src/backends/ocarina-backends-c_tree-nutils.ads
   - Also adapt the call sequence of a subprogram and a thread
     when we generate the call sequence

 * ocarina/src/backends/ocarina-backends-c_common-subprograms.adb
   - Also consider the device if the subprogram
     is part of a device implementation, map the correct
     arguments when mapping the spec of the subprogram
     and its call sequence.

 * ocarina/src/backends/ocarina-backends-c_common-mapping.adb
   ocarina/src/backends/ocarina-backends-c_common-mapping.ads
   - Add the __po_hi_device_id to the subprogram signatures
     that correspond to functions defined for the implementation
     of a driver



git-svn-id: https://tecsw.estec.esa.int/svn/taste/trunk/ocarina@2701 129961e7-ef38-4bb5-a8f7-c9a525a55882