usb: dwc3: disable USB core PHY management

The dwc3 driver manages its PHYs itself so the USB core PHY management
needs to be disabled.

Use the struct xhci_plat_priv hack added by commits 46034a99 ("usb:
host: xhci-plat: add platform data support") and f768e718 ("usb:
host: xhci-plat: add priv quirk for skip PHY initialization") to
propagate the setting for now.

Fixes: 4e88d4c0 ("usb: add a flag to skip PHY initialization to struct usb_hcd")
Fixes: 178a0bce

 ("usb: core: hcd: integrate the PHY wrapper into the HCD core")
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Cc: stable <stable@kernel.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20220825131836.19769-1-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>