mac80211: configure default wmm params correctly

Default WMM params have to be set according to beacon/probe response
information prior to authentication (or IBSS start/join); beacon queue
is configured only in IBSS. This does not affect the use of 'real' WMM
params as reported by AP.

Signed-off-by: Vladimir Koutny <vlado@ksp.sk>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>