ath9k_htc: Add a new WMI command to set a rate mask

This patch adds WMI_BITRATE_MASK_CMDID which can be
used by the set_bitrate_mask() handler.

Signed-off-by: Sujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/wmi.c b/drivers/net/wireless/ath/ath9k/wmi.c
index 463b76ab..f9b1eb4 100644
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -79,6 +79,8 @@
 		return "WMI_TX_STATS_CMDID";
 	case WMI_RX_STATS_CMDID:
 		return "WMI_RX_STATS_CMDID";
+	case WMI_BITRATE_MASK_CMDID:
+		return "WMI_BITRATE_MASK_CMDID";
 	}
 
 	return "Bogus";