dt-bindings: i2c: nvidia,tegra20-i2c: Specify the required properties

Specify the properties which are essential and which are not for the
Tegra I2C driver to function correctly. This was not added correctly when
the TXT binding was converted to yaml. All the existing DT nodes have
these properties already and hence this does not break the ABI.

dmas and dma-names which were specified as a must in the TXT binding
is now made optional since the driver can work in PIO mode if dmas are
missing.

Fixes: f10a9b72 ("dt-bindings: i2c: tegra: Convert to json-schema”)
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Cc: <stable@vger.kernel.org> # v5.17+
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Andi Shyti <andi@smida.it>
Link: https://lore.kernel.org/r/20250603153022.39434-1-akhilrajeev@nvidia.com