usb: dwc3: core: Clean up ULPI device

If dwc3_core_init_mode() fails with deferred probe,
next probe fails on sysfs with

sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:11.0/dwc3.0.auto/dwc3.0.auto.ulpi'

To avoid this failure, clean up ULPI device.

Cc: <stable@vger.kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>