USB: qcserial: support generic Qualcomm serial ports

No need to verify the interface layout when doing
interface number based matching.  We can safely trust
the device ID table in this case.

This allows the driver to support any USB interface
layout for non-Gobi 1k/2k+ devices.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>