mac80211: Make sure non-HT connection when IEEE80211_STA_TKIP_WEP_USED is set

It is possible that some broken AP might send HT IEs in it's
assoc response even though the STA has not sent them in assoc req
when WEP/TKIP is used as pairwise cipher suite. Also it is important
to check this bit before enabling ht mode in beacon receive path.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>