o add IEEE80211_F_JOIN flag to ieee80211_fix_rate to indicate a station
is joining a BSS; this is used to control whether or not we over-write
the basic rate bit in the calculated rate set
o fix ieee80211_fix_rate to honor IEEE80211_F_DODEL when IEEE80211_F_DONEGO
is not specified (e.g. when joining an ibss network)
o on sta join always delete unusable rates from the negotiated rate set,
this was being done only ibss networks but is also needed for 11g bss
with mixed stations
o on sta join delete unusable rates from the bss node's rate set, not the
scan table entry's rate set
o when calculating a rate set for new neighbors in an ibss caculate a
negotiated rate set so drivers are not presented with rates they should
not use
Submitted by: Sepherosa Ziehau (w/ modifications)
Obtained from: DragonFly
MFC after: 1 month
79edaebfe4