dt-bindings: i2c: tegra: Convert to json-schema

Convert the Tegra I2C controller bindings from plain text to json-schema
format.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211217165658.2650677-1-thierry.reding@gmail.com