[media] mceusb: don't claim multifunction device non-IR parts

There's a Realtek combo card reader and IR receiver device with multiple
usb interfaces on it. The mceusb driver is incorrectly grabbing all of
them. This change should make it bind to only interface 2 (patch based
on lsusb output on the linux-media list from Lucian Muresan).

Tested regression-free with the six mceusb devices I have myself.

Reported-by: Patrick Boettcher <pboettcher@kernellabs.com>
Reported-by: Lucian Muresan <lucianm@users.sourceforge.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>