dt-bindings: i2c: Convert imx lpi2c to json-schema

Convert the i.MX LPI2C binding to DT schema format using json-schema

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Link: https://lore.kernel.org/r/1591235358-15516-2-git-send-email-Anson.Huang@nxp.com


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