ath9k: implement coverage class support

Signed-off-by: Felix Fietkau <nbd@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 a7ff075..ab1f198 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -551,6 +551,7 @@
 	u32 *bank6Temp;
 
 	int16_t txpower_indexoffset;
+	int coverage_class;
 	u32 beacon_interval;
 	u32 slottime;
 	u32 globaltxtimeout;