Remove unused enum.
Remove unused enum.

Tarnyko/weston-xdg_surface_present,eyolfson/weston,xorgy/weston,sir-murray/weston,udoprog/weston,kwm81/weston,udoprog/weston,giucam/weston,Fantu/compositor-spice,xorgy/weston,Fantu/compositor-spice,Gnurou/weston,jonnylamb/weston,krezovic/weston,eyolfson/weston,mchalupa/weston,sir-murray/weston,krezovic/weston,giucam/weston,mchalupa/weston,Fantu/compositor-spice,kwm81/weston,jonnylamb/weston,Gnurou/weston,Tarnyko/weston-xdg_surface_present