Convert binding doc newwork.txt to yaml format.

HDLC part:
- Convert to "fsl,ucc-hdlc.yaml".
- Add missed reg and interrupt property.
- Update example to pass build.

ethernet part:
- Convert to net/fsl,cpm-enet.yaml
- Add 0x in example, which should be hex value
- Add ref to ethernet-controller.yaml

mdio part:
- Convert to net/fsl,cpm-mdio.yaml
- Add 0x in example, which should be hex value
- Add ref to mdio.yaml
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20240812165041.3815525-1-Frank.Li@nxp.comSigned-off-by: Rob Herring (Arm) <robh@kernel.org>