dt-bindings: usb: rockchip,dwc3: Move RK3399 to its own schema

dt-bindings: usb: rockchip,dwc3: Move RK3399 to its own schema

The rockchip,dwc3.yaml schema defines a single DWC3 node, but the RK3399
uses the discouraged parent wrapper node and child 'generic' DWC3 node.
The intent was to modify the RK3399 DTs to use a single node, but the DT
changes were rejected for ABI reasons. However, the schema was accepted
as-is.

To fix this, we need to move the RK3399 binding to its own schema file.
The RK3328 and RK3568 bindings are correct and use a single node.

Cc: Johan Jonker <jbx6244@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230124025936.3256213-2-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>