ath9k: enable 2GHz band only if the device supports it

Currently, the 2GHz band is enabled unconditionally, even if the device
does not support it.

Changes-licensed-under: ISC
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
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 46e1572..e2b0c73 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -620,7 +620,7 @@
 int ath9k_hw_init(struct ath_hw *ah);
 int ath9k_hw_reset(struct ath_hw *ah, struct ath9k_channel *chan,
 		   bool bChannelChange);
-void ath9k_hw_fill_cap_info(struct ath_hw *ah);
+int ath9k_hw_fill_cap_info(struct ath_hw *ah);
 bool ath9k_hw_getcapability(struct ath_hw *ah, enum ath9k_capability_type type,
 			    u32 capability, u32 *result);
 bool ath9k_hw_setcapability(struct ath_hw *ah, enum ath9k_capability_type type,