ath9k_hw: remove additional_swba_backoff

It is unused
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/hw.c

@@ -441,7 +441,6 @@ static void ath9k_hw_init_config(struct ath_hw *ah)
 {
 	ah->config.dma_beacon_response_time = 1;
 	ah->config.sw_beacon_response_time = 6;
-	ah->config.additional_swba_backoff = 0;
 	ah->config.ack_6mb = 0x0;
 	ah->config.cwm_ignore_extcca = 0;
 	ah->config.analog_shiftreg = 1;

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

@@ -280,7 +280,6 @@ struct ath9k_hw_capabilities {
 struct ath9k_ops_config {
 	int dma_beacon_response_time;
 	int sw_beacon_response_time;
-	int additional_swba_backoff;
 	int ack_6mb;
 	u32 cwm_ignore_extcca;
 	u32 pcie_waen;

drivers/net/wireless/ath/ath9k/mac.c

@@ -481,8 +481,7 @@ bool ath9k_hw_resettxqueue(struct ath_hw *ah, u32 q)
 			    | AR_Q_MISC_CBR_INCR_DIS0);
 		value = (qi->tqi_readyTime -
 			 (ah->config.sw_beacon_response_time -
-			  ah->config.dma_beacon_response_time) -
-			 ah->config.additional_swba_backoff) * 1024;
+			  ah->config.dma_beacon_response_time)) * 1024;
 		REG_WRITE(ah, AR_QRDYTIMECFG(q),
 			  value | AR_Q_RDYTIMECFG_EN);
 		REG_SET_BIT(ah, AR_DMISC(q),