cfg80211: support reloading regulatory database

If the regulatory database is loaded, and then updated, it may
be necessary to reload it. Add an nl80211 command to do this.

Note that this just reloads the database, it doesn't re-apply
the rules from it immediately.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/uapi/linux/nl80211.h

@@ -990,6 +990,8 @@
  *	&NL80211_CMD_CONNECT or &NL80211_CMD_ROAM. If the 4 way handshake failed
  *	&NL80211_CMD_DISCONNECT should be indicated instead.
  *
+ * @NL80211_CMD_RELOAD_REGDB: Request that the regdb firmware file is reloaded.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -1194,6 +1196,8 @@ enum nl80211_commands {
 
 	NL80211_CMD_PORT_AUTHORIZED,
 
+	NL80211_CMD_RELOAD_REGDB,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */