dt-bindings: mmc: Convert imx esdhc to json-schema

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

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Link: https://lore.kernel.org/r/1592450578-30140-1-git-send-email-Anson.Huang@nxp.com


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