mac80211: 802.11p OCB mode support

This patch adds 802.11p OCB (Outside the Context of a BSS) mode
support.

When communicating in OCB mode a mandatory wildcard BSSID
(48 '1' bits) is used.

The EDCA parameters handling function was changed to support
802.11p specific values.

The insertion of a newly discovered STAs is done in the similar way
as in the IBSS mode -- through the deferred insertion.

The OCB mode uses a periodic 'housekeeping task' for expiration of
disconnected STAs (in the similar manner as in the MESH mode).

New Kconfig option for verbose OCB debugging outputs is added.

Signed-off-by: Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -263,6 +263,7 @@ struct ieee80211_vif_chanctx_switch {
  * @BSS_CHANGED_BANDWIDTH: The bandwidth used by this interface changed,
  *	note that this is only called when it changes after the channel
  *	context had been assigned.
+ * @BSS_CHANGED_OCB: OCB join status changed
  */
 enum ieee80211_bss_change {
 	BSS_CHANGED_ASSOC		= 1<<0,
@@ -287,6 +288,7 @@ enum ieee80211_bss_change {
 	BSS_CHANGED_P2P_PS		= 1<<19,
 	BSS_CHANGED_BEACON_INFO		= 1<<20,
 	BSS_CHANGED_BANDWIDTH		= 1<<21,
+	BSS_CHANGED_OCB                 = 1<<22,
 
 	/* when adding here, make sure to change ieee80211_reconfig */
 };