ath10k: split ap/ibss wep key install process

Apparently it's not safe to install both pairwise
and groupwise keys on AP vdevs as it can cause
traffic to stop working in some multi-vif
(WPA+WEP) cases.

Fixes: ce90b271

 ("ath10k: fix multiple key static wep with ibss")
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>