ath5k: implement multi-rate retry support, fix tx status reporting

Clean up the tx status reporting, fix retry counters (short retries are
virtual collisions, not actual retries). Implement multi-rate retry
support.
This also fixes strong throughput fluctuations with rc80211_pid

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath5k/ath5k.h b/drivers/net/wireless/ath5k/ath5k.h
index 7134c40..53ea439 100644
--- a/drivers/net/wireless/ath5k/ath5k.h
+++ b/drivers/net/wireless/ath5k/ath5k.h
@@ -431,7 +431,9 @@
 	u16	ts_seqnum;
 	u16	ts_tstamp;
 	u8	ts_status;
-	u8	ts_rate;
+	u8	ts_rate[4];
+	u8	ts_retry[4];
+	u8	ts_final_idx;
 	s8	ts_rssi;
 	u8	ts_shortretry;
 	u8	ts_longretry;