Set the station to authorized on assoc event for open authentication

Set the station to authorized on assoc event for open authentication

This was done in handle_assoc_cb() in ieee802_11.c for drivers that use
hostapd SME/MLME. However, drivers that include SME/MLME implementation
do not use that function and the STA flag needs to be set when
processing the association notification. This is needed to get the STA
entry into showing the proper authorized state and to get the
AP-STA-CONNECTED/DISCONNECTED events on the control interface.

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