TODO:
- prepare private ieee80211 stack for merge with rtl8192su's version:
- - rename struct ieee80211_hdr_QOS to struct ieee80211_hdr_4addrqos
- add hwsec_active flag to struct ieee80211_device
- add bHwSec flag to cb_desc structure
- - switch ieee80211.h to use <linux/ieee80211.h>
- switch to use shared "librtl" instead of private ieee80211 stack
- switch to use LIB80211
- switch to use MAC80211