Add another vendor specific ID for BCM20702A0.  This has been tested and
works on hardware with this device.

output of usb-devices:
T: Bus=01 Lev=02 Prnt=02 Port=03 Cnt=04 Dev#= 6 Spd=12 MxCh= 0
D: Ver= 2.00 Cls=ff(vend.) Sub=01 Prot=01 MxPS=64 #Cfgs= 1
P: Vendor=0a5c ProdID=21e6 Rev=01.12
S: Manufacturer=Broadcom Corp
S: Product=BCM20702A0
S: SerialNumber=D0DF9AFB227B
C: #Ifs= 4 Cfg#= 1 Atr=e0 MxPwr=0mA
I: If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=01 Prot=01 Driver=(none)
I: If#= 1 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=01 Prot=01 Driver=(none)
I: If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
I: If#= 3 Alt= 0 #EPs= 0 Cls=fe(app. ) Sub=01 Prot=01 Driver=(none)
Signed-off-by: James M. Leddy <james.leddy@canonical.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>