cfg/mac80211: add regulatory classes IE during TDLS setup

Seems Broadcom TDLS peers (Nexus 5, Xperia Z3) refuse to allow TDLS
connection when channel-switching is supported but the regulatory
classes IE is missing from the setup request.
Add a chandef to reg-class translation function to cfg80211 and use it
to add the required IE during setup. For now add only the current
regulatory class as supported - it is enough to resolve the
compatibility issue.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 12a6121..c4d873b 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4903,6 +4903,17 @@
 bool ieee80211_operating_class_to_band(u8 operating_class,
 				       enum ieee80211_band *band);
 
+/**
+ * ieee80211_chandef_to_operating_class - convert chandef to operation class
+ *
+ * @chandef: the chandef to convert
+ * @op_class: a pointer to the resulting operating class
+ *
+ * Returns %true if the conversion was successful, %false otherwise.
+ */
+bool ieee80211_chandef_to_operating_class(struct cfg80211_chan_def *chandef,
+					  u8 *op_class);
+
 /*
  * cfg80211_tdls_oper_request - request userspace to perform TDLS operation
  * @dev: the device on which the operation is requested