ath9k: Trim rate table

Remove ctrl_rate, cw40index, sgi_index, ht_index and calculate
the rate index for TX status from the valid_rate_index that
is populated at initialization time.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/rc.h

@@ -160,10 +160,6 @@ struct ath_rate_table {
 		u32 user_ratekbps;
 		u8 ratecode;
 		u8 dot11rate;
-		u8 ctrl_rate;
-		u8 cw40index;
-		u8 sgi_index;
-		u8 ht_index;
 	} info[RATE_TABLE_SIZE];
 	u32 probe_interval;
 	u8 initial_ratemax;