ath9k: remove ath9k_ht_macmode

This is used just to determine how to program the MAC,
either for 20 MHz operation of 40 MHz so just use conf_is_ht40()

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/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 53ffe2a..92770cb 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -662,7 +662,7 @@
 void ath9k_hw_reset_tsf(struct ath_hw *ah);
 void ath9k_hw_set_tsfadjust(struct ath_hw *ah, u32 setting);
 bool ath9k_hw_setslottime(struct ath_hw *ah, u32 us);
-void ath9k_hw_set11nmac2040(struct ath_hw *ah, enum ath9k_ht_macmode mode);
+void ath9k_hw_set11nmac2040(struct ath_hw *ah);
 void ath9k_hw_beaconinit(struct ath_hw *ah, u32 next_beacon, u32 beacon_period);
 void ath9k_hw_set_sta_beacon_timers(struct ath_hw *ah,
 				    const struct ath9k_beacon_state *bs);