USB: qmi_wwan: Add quirk for Quectel EC20 Mini PCIe module

USB: qmi_wwan: Add quirk for Quectel EC20 Mini PCIe module

This device has same vendor and product IDs as G2K devices, but it has
different number of interfaces(4 vs 5) and also different interface
layout where EC20 has QMI on interface 4 instead of 0.

lsusb output:

	Bus 002 Device 003: ID 05c6:9215 Qualcomm, Inc. Acer Gobi 2000
	Device Descriptor:
	  bLength                18
	  bDescriptorType         1
	  bcdUSB               2.00
	  bDeviceClass            0 (Defined at Interface level)
	  bDeviceSubClass         0
	  bDeviceProtocol         0
	  bMaxPacketSize0        64
	  idVendor           0x05c6 Qualcomm, Inc.
	  idProduct          0x9215 Acer Gobi 2000 Wireless Modem
	  bcdDevice            2.32
	  iManufacturer           1 Quectel
	  iProduct                2 Quectel LTE Module
	  iSerial                 0
	  bNumConfigurations      1
	  Configuration Descriptor:
	    bLength                 9
	    bDescriptorType         2
	    wTotalLength          209
	    bNumInterfaces          5
	    bConfigurationValue     1
	    iConfiguration          0
	    bmAttributes         0xa0
	      (Bus Powered)
	      Remote Wakeup
	    MaxPower              500mA

Signed-off-by: Petr Štetiar <ynezz@true.cz>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>