net: usb: sr9700: support devices with virtual driver CD

net: usb: sr9700: support devices with virtual driver CD

Some SR9700 devices have an SPI flash chip containing a virtual driver
CD, in which case they appear as a device with two interfaces and
product ID 0x9702. Interface 0 is the driver CD and interface 1 is the
Ethernet device.

Link: https://github.com/name-kurniawan/usb-lan
Link: https://www.draisberghof.de/usb_modeswitch/bb/viewtopic.php?t=2185
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Link: https://patch.msgid.link/20251211062451.139036-1-enelsonmoore@gmail.com
[pabeni@redhat.com: fixes link tags]
Signed-off-by: Paolo Abeni <pabeni@redhat.com>