x11/device-manager-xi2: Remove heuristics for touchscreen devices
x11/device-manager-xi2: Remove heuristics for touchscreen devices

Devices that have touch valuator classes will be touchscreens or
touchpads; anything else should be ignored.

djdeath/clutter-multithreaded,djdeath/clutter-multithreaded,djdeath/clutter-multithreaded,djdeath/clutter-multithreaded