control: Add missing zone.hpp include to functor.hpp

Found this to be missing for the forward declaration of the Zone class
while testing the creation of trigger objects from JSON.

Change-Id: I3c5d19889c9eb1738add1ee9f4870f7d8e386ba0
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
1 file changed