drm/tegra: Add support for tiled buffer objects

The gr2d and gr3d engines work more efficiently on buffers with a tiled
memory layout. Allow created buffers to be marked as tiled so that the
display controller can scan them out properly.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Thierry Reding <treding@nvidia.com>