USB: sierra: QMI mode MC7710 moved to qcserial

The MC7710 in QMI mode does not support the vendor
specific USB requests used by this driver.  The most
noticable effect of this is a 5 second delay as each
serial port is probed, caused by the set_power_state
command timing out:

 [   17.434291] usbcore: registered new interface driver sierra
 [   17.434383] USB Serial support registered for Sierra USB modem
 [   17.434486] sierra 8-4:1.0: Sierra USB modem converter detected
 [   22.432413] usb 8-4: Sierra USB modem converter now attached to ttyUSB0
 [   22.432563] sierra 8-4:1.2: Sierra USB modem converter detected
 [   27.432410] usb 8-4: Sierra USB modem converter now attached to ttyUSB1
 [   27.432562] sierra 8-4:1.3: Sierra USB modem converter detected
 [   32.432463] usb 8-4: Sierra USB modem converter now attached to ttyUSB2

The MC7710 provide the same Qualcomm serial interfaces
as Gobi modules, and the qcserial driver has been extended
to support the module instead of this driver.

Cc: Anton Samokhvalov <pg83@yandex.ru>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>