disp: msm: dsi: fix DSI mode index parsing

The change fixes DSI mode index parsing required for setting
preferred node.

Change-Id: I6f91543843e697491c68d89b22103b2ac281e936
Signed-off-by: Satya Rama Aditya Pinapala <psraditya30@codeaurora.org>

msm/dsi/dsi_display.c

@@ -6931,12 +6931,12 @@ int dsi_display_get_modes(struct dsi_display *display,
 			}
 
 			memcpy(sub_mode, &display_mode, sizeof(display_mode));
-			sub_mode->mode_idx = array_idx;
 			array_idx++;
 
 			if (!dfps_caps.dfps_support || !support_video_mode)
 				continue;
 
+			sub_mode->mode_idx += (array_idx - 1);
 			curr_refresh_rate = sub_mode->timing.refresh_rate;
 			sub_mode->timing.refresh_rate = dfps_caps.dfps_list[i];