drm/tegra: gr2d: Correct swapped device-tree compatibles

The device-tree compatibles are swapped in the code, correct them.

Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Tested-by: Matt Merhar <mattmerhar@protonmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>