ath6kl: Update BSS information after connection

Since we may end up using a dummy BSS entry when roaming, allow one Beacon
frame -based bssinfo from the current BSS to be processed prior to starting
to filter all bssinfo events. This allows cfg80211 BSS table to be filled
with proper data in the roaming case where the full Beacon data may not
have been present at the time of roamed event.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>