Allow upload to an Arduino Due device from root of repo scons build.

Allow upload to an Arduino Due device from root of repo scons build.

Support to upload to an Arduino Due device was only added to the internal
CA Layer scons build. This commit mitigates this issue.

Change-Id: I7ffe3d38976b9de12fa987235d0ed1fe5305b6aa
Signed-off-by: Joseph Morrow <joseph.l.morrow@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/615
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jon A. Cruz <jonc@osg.samsung.com>
Reviewed-by: Erich Keane <erich.keane@intel.com>