disp: msm: dsi: add DCS get scan line command

Add DCS command to read the panel scan line value and associated
time stamp in nano-seconds.

Change-Id: I06a76d3a6c5ad7a2e7681413c741e5b97b34d73f
Signed-off-by: Amine Najahi <quic_anajahi@quicinc.com>

msm/dsi/dsi_defs.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2021-2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2021-2023 Qualcomm Innovation Center, Inc. All rights reserved.
  * Copyright (c) 2016-2021, The Linux Foundation. All rights reserved.
  */
 
@@ -366,6 +366,7 @@ enum dsi_video_traffic_mode {
  * @post_wait_ms:        post wait duration
  * @ctrl:                index of DSI controller
  * @ctrl_flags:          controller flags
+ * @ts:                  dsi command time stamp in nano-seconds.
  */
 struct dsi_cmd_desc {
 	struct mipi_dsi_msg msg;
@@ -373,6 +374,7 @@ struct dsi_cmd_desc {
 	u32  post_wait_ms;
 	u32 ctrl;
 	u32 ctrl_flags;
+	ktime_t ts;
 };
 
 /**