[ARM] pxa/corgi: fix incorrect default GPIO for UDC Vbus

There is no such GPIO for udc vbus sensing, put '-1' instead of default
'0' as '0' does mean a valid GPIO.
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>

arch/arm/mach-pxa/corgi.c

@@ -457,6 +457,7 @@ static struct pxaficp_platform_data corgi_ficp_platform_data = {
  * USB Device Controller
  */
 static struct pxa2xx_udc_mach_info udc_info __initdata = {
+	.gpio_vbus		= -1,
 	/* no connect GPIO; corgi can't tell connection status */
 	.gpio_pullup		= CORGI_GPIO_USB_PULLUP,
 };