wifi: mac80211: call drv_sta_state() under sdata_lock() in reconfig

Currently, other paths calling drv_sta_state() hold the mutex
and therefore drivers can assume that, and look at links with
that protection. Fix that for the reconfig path as well; to
do it more easily use ieee80211_reconfig_stations() for the
AP/AP_VLAN station reconfig as well.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>