libinput: remove unused #define
libinput: remove unused #define

Reviewed-by: Peter Hutterer <b9c50af7afa7642f6f854434cda9ffe54ece8b85@who-t.net>

Fantu/compositor-spice,sir-murray/weston,krezovic/weston,kwm81/weston,giucam/weston,Gnurou/weston,giucam/weston,kwm81/weston,sir-murray/weston,Fantu/compositor-spice,Gnurou/weston,Fantu/compositor-spice,krezovic/weston