hw/arm: Add missing XLNX_ZYNQMP_ARM -> USB_DWC3 Kconfig dependency

hw/arm: Add missing XLNX_ZYNQMP_ARM -> USB_DWC3 Kconfig dependency

Since commit acc0b8b05a when running the ZynqMP ZCU102 board with
a QEMU configured using --without-default-devices, we get:

  $ qemu-system-aarch64 -M xlnx-zcu102
  qemu-system-aarch64: missing object type 'usb_dwc3'
  Abort trap: 6

Fix by adding the missing Kconfig dependency.

Fixes: acc0b8b05a ("hw/arm/xlnx-zynqmp: Connect ZynqMP's USB controllers")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20230216092327.2203-1-philmd@linaro.org
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>