CI: xilinx_versal_virt: disable USB_DWC3

CI: xilinx_versal_virt: disable USB_DWC3

The CI uses the following command to launch xilinx_versal_virt_defconfig:

    qemu-system-aarch64 -M xlnx-versal-virt \
    -display none -m 4G -serial mon:stdio \
    -device loader,file=u-boot,cpu-num=0

'usb start' or invoking eth_bootdev_hunt leads to a crash when function
dwc3_core_init() tries to access a register at offset 0xc704 (DWC3_DCTL)
relative to the register start address 0xfe20c100.

Disable CONFIG_USB_DWC3 in the CI until the driver problem is fixed.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>