dt-bindings: display: Update Tegra DPAUX documentation

Update the DPAUX compatibility string information for Tegra124, Tegra132
and Tegra210.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>