dt-bindings: usb: qcom,dwc3: Validate DWC3 sub-node

dt-bindings: usb: qcom,dwc3: Validate DWC3 sub-node

Qualcomm msm8996/sc7180/sdm845 DWC3 compatible DT nodes are supposed to
have a DWC USB3 compatible sub-node to describe a fully functioning USB
interface. Let's use the available DWC USB3 DT schema to validate the
Qualcomm DWC3 sub-nodes.

Note since the generic DWC USB3 DT node is supposed to be named as generic
USB HCD ("^usb(@.*)?") one we have to accordingly fix the sub-nodes name
regexp and fix the DT node example.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20201210090944.16283-19-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>