rsi: add bluetooth rx endpoint

USB endpoint 1 is used for WLAN which is presently in use.
USB endpoint 2 is introduced for BT Rx traffic. Enumeration
of Rx BT endpoint and submitting Rx BT URB are added.

>From /sys/kernel/debug/usb/devices,
Ad=81(I) is for WLAN EP IN and Ad=01(O) is for Wlan EP OUT.
Ad=82(I) is for BT EP IN and Ad=02(O) is for BT EP OUT.

T:  Bus=01 Lev=01 Prnt=01 Port=09 Cnt=03 Dev#=  4 Spd=480  MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=1618 ProdID=9113 Rev= 0.02
S:  Manufacturer=Redpine Signals, Inc.
S:  Product=Wireless USB Network Module
S:  SerialNumber=000000000001
C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=  2mA
I:* If#= 0 Alt= 0 #EPs= 6 Cls=00(>ifc ) Sub=00 Prot=00 Driver=(none)
E:  Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=83(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=03(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms

Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
Signed-off-by: Prameela Rani Garnepudi <prameela.j04cs@gmail.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>