rt2x00: Optimize configuration handling

Implement latest changed from mac80211 configuration
handling to optmize configuration handling in rt2x00.

 * Remove set_retry_limit callback function, handled
   through config()
 * Move config_antenna to its own callback function,
   it isn't handled by mac80211 anymore
 * Use IEEE80211_CONF_CHANGED_* flags and remove manual
   checks
 * Removed deprecated short slot setting through config()
   and put it in config_erp() through which mac80211 now
   configures it
 * Remove config_phymode() and move contents to config_erp()
   since it only managed the basic rates which is now
   determined by mac80211 through config_erp().

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00lib.h b/drivers/net/wireless/rt2x00/rt2x00lib.h
index 797eb61..9f214f8 100644
--- a/drivers/net/wireless/rt2x00/rt2x00lib.h
+++ b/drivers/net/wireless/rt2x00/rt2x00lib.h
@@ -96,7 +96,8 @@
 void rt2x00lib_config_antenna(struct rt2x00_dev *rt2x00dev,
 			      enum antenna rx, enum antenna tx);
 void rt2x00lib_config(struct rt2x00_dev *rt2x00dev,
-		      struct ieee80211_conf *conf, const int force_config);
+		      struct ieee80211_conf *conf,
+		      const unsigned int changed_flags);
 
 /**
  * DOC: Queue handlers