Add client driver for 2D device, and IOCTLs to pass work to host1x
channel for 2D.

Also adds functions that can be called to access sync points from
DRM.
Signed-off-by: NArto Merilainen <amerilainen@nvidia.com>
Signed-off-by: NTerje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: NThierry Reding <thierry.reding@avionic-design.de>
Tested-by: NThierry Reding <thierry.reding@avionic-design.de>
Tested-by: NErik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>