The "swap-dx-lanes" was never described as uint8 in original TXT
bindings and Linux driver expects uint32. Fix the type to match Linux
driver expectation.
Fixes: fff61d4ccf3d ("dt-bindings: usb: usb251xb: Convert to YAML schema")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>