Remove proto_tree_add_text from ZigBee dissectors.

Change-Id: I0488cb0ab33f2cc6dee227f1bfacec58eafc4190
Reviewed-on: https://code.wireshark.org/review/6055
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>