iwlwifi: tx fifo queue flush command

Add host command and structure for tx fifo queue flush

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-hcmd.c b/drivers/net/wireless/iwlwifi/iwl-hcmd.c
index 51f89e7..258d059 100644
--- a/drivers/net/wireless/iwlwifi/iwl-hcmd.c
+++ b/drivers/net/wireless/iwlwifi/iwl-hcmd.c
@@ -49,6 +49,7 @@
 		IWL_CMD(REPLY_ADD_STA);
 		IWL_CMD(REPLY_REMOVE_STA);
 		IWL_CMD(REPLY_REMOVE_ALL_STA);
+		IWL_CMD(REPLY_TXFIFO_FLUSH);
 		IWL_CMD(REPLY_WEPKEY);
 		IWL_CMD(REPLY_3945_RX);
 		IWL_CMD(REPLY_TX);