groovy/doc: add pr2_controllers dependency to katana_driver

The indexer gets confused while trying to guess what debs I would like to
have installed; it thinks I want
`ros-groovy-pr2-controllers-msgs` and freaks out because that deb doesn't 
exist, refusing to even generate a groovy link for the documentation (so 
there even isn't any link to the error output on the wiki). Maybe we can work
around that bug by adding the dependency to the correct stack manually, let's
wait and see in a few days.

See https://github.com/ros/rosdistro/issues/1235