dt-bindings: usb: st,st-ohci-300x: convert to DT schema

Convert STMicroelectronics USB OHCI Controller binding to DT schema.

Signed-off-by: Charan Pedumuru <charan.pedumuru@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260224-st-usb-v2-1-e8b7cb6524c6@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>