build: depend on generated protocol headers
build: depend on generated protocol headers

Fixes the build failure where the protocol headers were not generated at
all before compiling src/.libs/libwayland_server_la-wayland-server.o.

The failure was reproducable by starting fresh with 'git clean -dxf' and
not having any wayland headers installed system-wide.

Signed-off-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

tulcod/wayland,sir-murray/wayland,eyolfson/wayland,sir-murray/wayland,bitfactor/wayland,sir-murray/wayland,mchalupa/wayland,abooij/wayland,eyolfson/wayland,tulcod/wayland,abooij/wayland,tulcod/wayland,bitfactor/wayland,mchalupa/wayland,bitfactor/wayland,mchalupa/wayland,abooij/wayland,eyolfson/wayland