usbnet: ipheth: Simplify device detection

All Apple products use the same protocol for tethering over USB.
To simplify the code and make it future proof, use
USB_VENDOR_AND_INTERFACE_INFO() instead of
USB_DEVICE_AND_INTERFACE_INFO() to automatically detect and support
all existing and future Apple products using the same interface.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>