evdev: make evdev_notify_keyboard_focus() independent of evdev_seat
evdev: make evdev_notify_keyboard_focus() independent of evdev_seat

in preparation of removing evdev_seat

Signed-off-by: Pekka Paalanen <6c0263d81461c956d504307112a4ce25eaacc3d1@gmail.com>

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