dt-bindings: usb: microchip,usb2514: Fix reference USB device schema

dt-bindings: usb: microchip,usb2514: Fix reference USB device schema

An USB hub is not a HCD, but an USB device. Fix the referenced schema
accordingly.

Fixes: bfbf2e4b77e2 ("dt-bindings: usb: Document the Microchip USB2514 hub")
Cc: stable@vger.kernel.org
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20240815113132.372542-1-alexander.stein@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>