elm_entry: make the hoversel not focusable
the hoversel is added to a entry while entrys are not build for handling
children focus. Disabling this prevents wrong focus operations.
Reviewers: zmike, committers, netstar
Reviewed By: netstar
Subscribers: cedric, committers, zmike
Maniphest Tasks: T7163
Differential Revision: https://phab.enlightenment.org/D6695