Makes use of weston-direct-display protocol to pass the dmabuf
straight to the display-controller if such a path is possible.

Removes the Y_INVERT flag in case that was passed, and notifies
the user about it, as the weston implementation would force going
through the renderer when passing the Y_INVERT flag, but in the same
time direct-display avoids any GPU import so having them both in the
same time would result into weston refusing the create a buffer.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>