ath9k: Store subsystem id in struct hw_version

This subsystem id will be used later to turn on the btcoex
support.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@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 a592f1a..64ea547 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -390,6 +390,7 @@
 	u16 phyRev;
 	u16 analog5GhzRev;
 	u16 analog2GhzRev;
+	u16 subsysid;
 };
 
 /* Generic TSF timer definitions */