ath9k_htc: Add support of AirTies 1eda:2315 AR9271 device

T:  Bus=01 Lev=02 Prnt=02 Port=02 Cnt=01 Dev#=  7 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=ff(vend.) Sub=ff Prot=ff MxPS=64 #Cfgs=  1
P:  Vendor=1eda ProdID=2315 Rev=01.08
S:  Manufacturer=ATHEROS
S:  Product=USB2.0 WLAN
S:  SerialNumber=12345
C:  #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 6 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)

Signed-off-by: Dmitry Tunin <hanipouspilot@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>