bcams will atleast work when
connected through an usb-2.0 hub when the microphone is not used.

As an added bonus this patch avoids extra destroy/create input urb cycles
when we end up falling back to a lower speed alt setting because of bandwidth
limitations.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
ÉCzú–