Add option to reject authentication on 2.4 GHz from dualband STA

Add option to reject authentication on 2.4 GHz from dualband STA

The new no_auth_if_seen_on=<ifname> parameter can now be used to
configure hostapd to reject authentication from a station that was seen
on another radio.

This can be used with enabled track_sta_max_num configuration on another
interface controlled by the same hostapd process to reject
authentication attempts from a station that has been detected to be
capable of operating on another band, e.g., to try to reduce likelihood
of the station selecting a 2.4 GHz BSS when the AP operates both a 2.4
GHz and 5 GHz BSS concurrently.

Note: Enabling this can cause connectivity issues and increase latency for
connecting with the AP.

Signed-off-by: Jouni Malinen <j@w1.fi>