headers: sync DRM_MODE_ROTATE/REFLECT defines from kernel v4.14-rc1

Add the new DRM_MODE_ROTATE_* and DRM_MODE_REFLECT_* defines from v4.14-rc1
kernel.

Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Robert Foss <robert.foss@collabora.com>
Signed-off-by: Rob Herring <robh@kernel.org>