dt-bindings: i2c: Convert Synquacer I2C to DT schema

Convert the Socionext Synquacer I2C binding to DT schema format.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221209171658.3352119-1-robh@kernel.org


Signed-off-by: Rob Herring <robh@kernel.org>