dt-bindings: usb: introduce nxp,imx-dwc3

dt-bindings: usb: introduce nxp,imx-dwc3

The i.MX USB glue and DWC3 core are closely coupled. Describe the i.MX
USB block in a single block will bring more benefits than a parent-child
relation. The new binding is used to describe flattened usb controller
node. It's a copy of the legacy binding fsl,imx8mp-dwc3.yaml with the
needed modifications.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://patch.msgid.link/20260212-add-flatten-dts-based-dwc3-imx-driver-v5-1-ff04a75ce221@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>