FT: Fix hostapd with driver-based SME to authorize the STA

FT: Fix hostapd with driver-based SME to authorize the STA

The driver-based SME case did not set STA flags properly to the kernel
in the way that hostapd-SME did in ieee802_11.c. This resulted in the FT
protocol case not marking the STA entry authorized. Fix that by handling
the special WLAN_AUTH_FT case in hostapd_notif_assoc() and also add the
forgotten hostapd_set_sta_flags() call to synchronize these flag to the
driver.

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