ath10k: add quiet mode support for QCA6174/QCA9377

To enable thermal throttling for QCA6174 and QCA9377,
implement gen_pdev_set_quiet_mode for them.
With this change, quiet period for QCA6174/QCA9377 can
be also set/get via debugfs.
Usage:
To set quiet period:
 echo <period> > /sys/kernel/debug/ieee80211/phyX/ath10k/quiet_period
To get the current quiet period:
 cat /sys/kernel/debug/ieee80211/phyX/ath10k/quiet_period

This change has been verified with
QCA6174 hw3.2(fw: WLAN_RM.4.4.1-00102-QCARMSWP-1).

Signed-off-by: Yu Wang <yyuwang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/ath10k/wmi-tlv.h

@@ -1,6 +1,7 @@
 /*
  * Copyright (c) 2005-2011 Atheros Communications Inc.
  * Copyright (c) 2011-2017 Qualcomm Atheros, Inc.
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -1952,6 +1953,21 @@ struct wmi_tlv_wow_add_del_event_cmd {
 	__le32 event_bitmap;
 } __packed;
 
+/* Command to set/unset chip in quiet mode */
+struct wmi_tlv_set_quiet_cmd {
+	__le32 vdev_id;
+
+	/* in TUs */
+	__le32 period;
+
+	/* in TUs */
+	__le32 duration;
+
+	/* offset in TUs */
+	__le32 next_start;
+	__le32 enabled;
+} __packed;
+
 struct wmi_tlv_wow_enable_cmd {
 	__le32 enable;
 } __packed;