Atheros wlan module note

- set athx mac address
ath_vap_create(), if_ath.c

- send packets out of vap sta to home ap
ieee80211_send_setup(), ieee80211_mgmt.c

- send packets out between vaps(vap ap->sta)
ieee80211_ibss2ap_header() in ieee80211_encap_80211(), ieee80211_output.c

- receive packets for both vap ap and sta
ieee80211_aponly.c