mac80211: add documentation book

Quite a while ago I started this book. The required kernel-doc
patches have since gone into the tree so it is now possible to
build the book in mainline.

The actual documentation is still rather incomplete and not all
things are linked into the book, but this enables us to edit
the documentation collaboratively, hopefully driver authors can
add documentation based on their experience with mac80211.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 6aca472..d002b1c 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -407,7 +407,6 @@
  * @channel: the channel to tune to
  */
 struct ieee80211_conf {
-	unsigned int regulatory_domain;
 	int radio_enabled;
 
 	int beacon_int;
@@ -437,6 +436,7 @@
  * @IEEE80211_IF_TYPE_WDS: interface in WDS mode.
  * @IEEE80211_IF_TYPE_VLAN: VLAN interface bound to an AP, drivers
  *	will never see this type.
+ * @IEEE80211_IF_TYPE_MESH_POINT: 802.11s mesh point
  */
 enum ieee80211_if_types {
 	IEEE80211_IF_TYPE_INVALID,
@@ -1096,8 +1096,9 @@
 /**
  * ieee80211_register_hw - Register hardware device
  *
- * You must call this function before any other functions
- * except ieee80211_register_hwmode.
+ * You must call this function before any other functions in
+ * mac80211. Note that before a hardware can be registered, you
+ * need to fill the contained wiphy's information.
  *
  * @hw: the device to register as returned by ieee80211_alloc_hw()
  */