Add xf86-input-libinput support for X11 mouse backend.
Added libinput support to X11 backend. It also adds an new option to backend
which is only available to libinput device currently.
Test Plan: Manually tested and inspect with xinput tool.
Reviewers: ngraham, Plasma, jriddell
Reviewed By: ngraham, Plasma, jriddell
Subscribers: subdiff, jriddell, apol, rkflx, plasma-devel
Differential Revision: https://phabricator.kde.org/D8798