ath9k_hw: remove warning in ath9k_hw_def_get_num_ant_config

This patch fixes following warning

drivers/net/wireless/ath/ath9k/eeprom_def.c: In function 'ath9k_hw_def_get_num_ant_config'
drivers/net/wireless/ath/ath9k/eeprom_def.c:1425:47: warning: comparison
			between 'enum ath9k_hal_freq_band' and 'enum ieee80211_band'

Signed-off-by: Rajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/eeprom.h b/drivers/net/wireless/ath/ath9k/eeprom.h
index 090778d..e583421 100644
--- a/drivers/net/wireless/ath/ath9k/eeprom.h
+++ b/drivers/net/wireless/ath/ath9k/eeprom.h
@@ -672,7 +672,8 @@
 	bool (*fill_eeprom)(struct ath_hw *hw);
 	int (*get_eeprom_ver)(struct ath_hw *hw);
 	int (*get_eeprom_rev)(struct ath_hw *hw);
-	u8 (*get_num_ant_config)(struct ath_hw *hw, enum ieee80211_band band);
+	u8 (*get_num_ant_config)(struct ath_hw *hw,
+				 enum ath9k_hal_freq_band band);
 	u32 (*get_eeprom_antenna_cfg)(struct ath_hw *hw,
 				      struct ath9k_channel *chan);
 	void (*set_board_values)(struct ath_hw *hw, struct ath9k_channel *chan);