net: qmi_wwan: add ZTE MF880

The driver description files gives these names to the vendor specific
functions on this modem:

 diag: VID_19D2&PID_0284&MI_00
 nmea: VID_19D2&PID_0284&MI_01
 at:   VID_19D2&PID_0284&MI_02
 mdm:  VID_19D2&PID_0284&MI_03
 net:  VID_19D2&PID_0284&MI_04

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index 9b950f5..91d7cb9 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -433,6 +433,7 @@
 	{QMI_FIXED_INTF(0x19d2, 0x0199, 1)},	/* ZTE MF820S */
 	{QMI_FIXED_INTF(0x19d2, 0x0200, 1)},
 	{QMI_FIXED_INTF(0x19d2, 0x0257, 3)},	/* ZTE MF821 */
+	{QMI_FIXED_INTF(0x19d2, 0x0284, 4)},	/* ZTE MF880 */
 	{QMI_FIXED_INTF(0x19d2, 0x0326, 4)},	/* ZTE MF821D */
 	{QMI_FIXED_INTF(0x19d2, 0x1008, 4)},	/* ZTE (Vodafone) K3570-Z */
 	{QMI_FIXED_INTF(0x19d2, 0x1010, 4)},	/* ZTE (Vodafone) K3571-Z */