With the help from drm_atomic_helper_check_plane_state function, clipping
now handles planes to be partially or totally off-screen. The plane is
disabled if it is not visible.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190110151020.30468-4-peda@axentia.se