ath9k: now move ath9k_hw_btcoex_set_weight() to btcoex.c

After some necessary cleanups we now move ath9k_hw_btcoex_set_weight()
to where it belongs.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/btcoex.h b/drivers/net/wireless/ath/ath9k/btcoex.h
index 296ddd8..971d200 100644
--- a/drivers/net/wireless/ath/ath9k/btcoex.h
+++ b/drivers/net/wireless/ath/ath9k/btcoex.h
@@ -70,6 +70,9 @@
 void ath9k_hw_btcoex_init_2wire(struct ath_hw *ah);
 void ath9k_hw_btcoex_init_3wire(struct ath_hw *ah);
 void ath9k_hw_init_btcoex_hw(struct ath_hw *ah, int qnum);
+void ath9k_hw_btcoex_set_weight(struct ath_hw *ah,
+				u32 bt_weight,
+				u32 wlan_weight);
 void ath9k_hw_btcoex_enable(struct ath_hw *ah);
 void ath9k_hw_btcoex_disable(struct ath_hw *ah);