The current code can't deal with framebuffers with an offset. Return an
error when trying to create such a framebuffer until the rest of the
code is fixed to handle them.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>