ath6kl: add support wmi rate tables with mcs15

Some of the firmware versions support rate tables up to mcs15, add support for
that.

Signed-off-by: Jessica Wu <wjessica@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath6kl/core.h

@@ -145,6 +145,9 @@ enum ath6kl_fw_capability {
 	/* use low priority endpoint for all data */
 	ATH6KL_FW_CAPABILITY_MAP_LP_ENDPOINT,
 
+	/* ratetable is the 2 stream version (max MCS15) */
+	ATH6KL_FW_CAPABILITY_RATETABLE_MCS15,
+
 	/* this needs to be last */
 	ATH6KL_FW_CAPABILITY_MAX,
 };