mac80211: introduce hw config change flags

This makes mac80211 notify the driver which configuration
actually changed, e.g. channel etc.

No driver changes, this is just plumbing, driver authors are
expected to act on this if they want to.

Also remove the HW CONFIG debug printk, it's incorrect, often
we configure something else.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 6b85428..2e81af1 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -3320,11 +3320,12 @@
 	return err;
 }
 
-static int b43_op_config(struct ieee80211_hw *hw, struct ieee80211_conf *conf)
+static int b43_op_config(struct ieee80211_hw *hw, u32 changed)
 {
 	struct b43_wl *wl = hw_to_b43_wl(hw);
 	struct b43_wldev *dev;
 	struct b43_phy *phy;
+	struct ieee80211_conf *conf = &hw->conf;
 	unsigned long flags;
 	int antenna;
 	int err = 0;