USB: serial: option: Ignore card reader interface on Huawei E1750

Hi,

my Huawei 3G modem has an embedded Smart Card reader which causes
trouble when the modem is being detected (a bunch of "<warn>  (ttyUSBx):
open blocked by driver for more than 7 seconds!" in messages.log). This
trivial patch corrects the problem for me. The modem identifies itself
as "12d1:1406 Huawei Technologies Co., Ltd. E1750" in lsusb although the
description on the body says "Model E173u-1"

Signed-off-by: Michal Malý <madcatxster@prifuk.cz>
Cc: Bjørn Mork <bjorn@mork.no>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>