efl: support wayland, egl

Allow EFL to build with Wayland support.
Allow EFL to build with EGL support (when combined with
Wayland support, it effectively achieves GL acceleration
under a Wayland compositor).

Signed-off-by: Manuel Bachmann <manuel.bachmann@iot.bzh>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>