cfg80211: provide channel to join_mesh function

Just like the AP mode patch, instead of setting
the channel and then joining the mesh network,
provide the channel to join the network on to
the join_mesh() function.

Like in AP mode, you can also give the channel
to the join-mesh nl80211 command now.

Unlike AP mode, it picks a default channel if
none was given.

As libertas uses mesh mode interfaces but has
no join_mesh callback and we can't simply break
it, keep some compatibility code for that case
and configure the channel directly for it.

In the non-libertas case, where we store the
channel until join, allow setting it while the
interface is down.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index a54fb89..4c90c44 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -831,6 +831,8 @@
 
 /**
  * struct mesh_setup - 802.11s mesh setup configuration
+ * @channel: the channel to start the mesh network on
+ * @channel_type: the channel type to use
  * @mesh_id: the mesh ID
  * @mesh_id_len: length of the mesh ID, at least 1 and at most 32 bytes
  * @sync_method: which synchronization method to use
@@ -845,6 +847,8 @@
  * These parameters are fixed when the mesh is created.
  */
 struct mesh_setup {
+	struct ieee80211_channel *channel;
+	enum nl80211_channel_type channel_type;
 	const u8 *mesh_id;
 	u8 mesh_id_len;
 	u8 sync_method;