wcn36xx: Enable firmware offloaded keepalive

This patch calls wcn36xx_smd_keep_alive_req() on the STA patch immediately
after associating with an AP.

This will cause the firmware to send a NULL packet out to the AP every 30
seconds, thus offloading keep-alive processing from the SoC to the
firmware.
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201103121735.291324-4-bryan.odonoghue@linaro.org

drivers/net/wireless/ath/wcn36xx/main.c

@@ -910,6 +910,7 @@ static void wcn36xx_bss_info_changed(struct ieee80211_hw *hw,
 			 * place where AID is available.
 			 */
 			wcn36xx_smd_config_sta(wcn, vif, sta);
+			wcn36xx_enable_keep_alive_null_packet(wcn, vif);
 		} else {
 			wcn36xx_dbg(WCN36XX_DBG_MAC,
 				    "disassociated bss %pM vif %pM AID=%d\n",