Create vnt_fill_txkey as mac80211 replacement for s_vFillTxKey.
Create vnt_tx_packet which a merger of s_bPacketToWirelessUsb, nsDMA_tx_packet
and csMgmt_xmit using mac80211 signalling.
Create vnt_beacon_xmit as mac80211 replacement for csBeacon_xmit. Changing
header in vnt_beacon_buffer to struct ieee80211_mgmt deleting some of
old code. vnt_beacon_make is needed to make beacon for vnt_beacon_xmit.
Create vnt_beacon_enable as mac80211 call to enable beacon.
vnt_fill_ieee80211_rts is modified to use struct ieee80211_hdr instead of
struct ethhdr and access to tx_context.
In s_nsBulkOutIoCompleteWrite modify context handling