ath9k: Add CTWindow support

Since CTWindow can be used for improving discoverability,
fill this field in the NoA Attribute properly.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index c690601..b4ac51e 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -572,6 +572,8 @@
 /* VIFs */
 /********/
 
+#define P2P_DEFAULT_CTWIN 10
+
 struct ath_vif {
 	struct list_head list;