Bluetooth: Adding USB device 13d3:3375 as an Atheros AR3012.

The bluetooth module in the Asus UX31/UX21 is based on Atheros AR3012
and requires a firmware to be uploaded before it's usable.

output of usb-devices for this module:
T:  Bus=01 Lev=02 Prnt=02 Port=07 Cnt=03 Dev#=  6 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=13d3 ProdID=3375 Rev=00.02
S:  Manufacturer=Atheros Communications
S:  Product=Bluetooth USB Host Controller
S:  SerialNumber=Alaska Day 2006
C:  #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=100mA
I:  If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
I:  If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb

Signed-off-by: Eran <eran@over-here.org>
Tested-by: Michal Labedzki <michal.labedzki@tieto.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>