Fix make install rules for all examples in QtPositioning

This was highlighted during the testing of the Qt 5.2.0 package.

Change-Id: Iab1e6f5f1e1a8ceb62fc44658ec12fb131ccad65
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>