ath6kl: Maintain firmware interface index in struct ath6kl_vif

Pass this index to target in wmi commands to specify the interface
for which the command needs to be handled.

Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --cc drivers/net/wireless/ath/ath6kl/cfg80211.c
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/cfg80211.h
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/core.h
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/debug.c
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/init.c
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/main.c
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/sdio.c
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/txrx.c
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/wmi.c
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/wmi.h
Simple merge