This commit adds support (an ID, really) for D-Link DWM-157 hardware
version C1 USB modem to option driver.

According to manufacturer-provided Windows INF file the device has four
serial ports:
"D-Link HSPA+DataCard Diagnostics Interface" (interface 2; modem port),
"D-Link HSPA+DataCard NMEA Device" (interface 3),
"D-Link HSPA+DataCard Speech Port" (interface 4),
"D-Link HSPA+DataCard Debug Port" (interface 5).

usb-devices output:
T:  Bus=05 Lev=01 Prnt=01 Port=04 Cnt=01 Dev#=  3 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=2001 ProdID=7d0e Rev=03.00
S:  Manufacturer=D-Link,Inc
S:  Product=D-Link DWM-157
C:  #Ifs= 7 Cfg#= 1 Atr=a0 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(commc) Sub=0e Prot=00 Driver=cdc_mbim
I:  If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=02 Driver=cdc_mbim
I:  If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=02 Prot=01 Driver=option
I:  If#= 3 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 4 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 5 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
I:  If#= 6 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>