Link watches to callbacks

Callbacks must ultimately be triggered when a property
is updated by a watch.  Add that support.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Change-Id: I20130a11c19ddcf2c4ae45800f2068b31950bcd6
diff --git a/src/templates/generated.mako.hpp b/src/templates/generated.mako.hpp
index a4819e2..15835bf 100644
--- a/src/templates/generated.mako.hpp
+++ b/src/templates/generated.mako.hpp
@@ -188,7 +188,12 @@
         {
 % for w in watches:
             std::make_unique<PropertyWatchOfType<${w.datatype}, SDBusPlus>>(
+    % if w.callback is None:
                 ConfigPropertyIndicies::get()[${w.instances}]),
+    % else:
+                ConfigPropertyIndicies::get()[${w.instances}],
+                *ConfigPropertyCallbacks::get()[${w.callback}]),
+    % endif
 % endfor
         };
         return propertyWatches;