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/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
index b883b17..e2ae98f 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
@@ -968,7 +968,7 @@
 }
 
 static u8 ath9k_hw_ar9300_get_num_ant_config(struct ath_hw *ah,
-					     enum ieee80211_band freq_band)
+					     enum ath9k_hal_freq_band freq_band)
 {
 	return 1;
 }