ath9k: get rid of tx_info_priv

This patch removes the need for separately allocated private tx info
data in ath9k and brings the driver one small step closer to using the
mac80211 rate control API properly.

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/common.h b/drivers/net/wireless/ath/ath9k/common.h
index 292e3d8..4e11760 100644
--- a/drivers/net/wireless/ath/ath9k/common.h
+++ b/drivers/net/wireless/ath/ath9k/common.h
@@ -81,6 +81,7 @@
 	u16 bf_flags;
 	struct ath_buf_state bf_state;
 	dma_addr_t bf_dmacontext;
+	struct ath_wiphy *aphy;
 };
 
 struct ath_atx_tid {