This has now been deprecated in libinput, the only known user of this
property. It was never set for any device and weston and mutter, maybe
other compositors, never added the code required to parse it.
The benefit we could get in the UI from handling tilt differently to
wheel is tiny and the lack of support shows that it isn't of interest to
anyone. Let's remove this.
See also
https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/444
projects / thirdparty / systemd.git / commit
