evdev: remove useless field from device structure
evdev: remove useless field from device structure

We'll want to enhance later the driver regarding the tool being used, but for
now just remove unused bits.

Signed-off-by: Tiago Vignatti <f080760b2054d506aacc8dee97f8804c19fbc3aa@intel.com>

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