disp: msm: avoid logging event logs by default in sde_dbg_dump

Avoid printing the eventlogs in kernel logs during display debug
logging through sde_dbg_dump to avoid excessive logging. Add a
debugfs node to control in-mem/in-log mode of eventlogs to help
in debugging.

Change-Id: If98b129cafa9d29eccd0c44285f1058876f3e1ea
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>

msm/sde_dbg_evtlog.c

@@ -210,7 +210,7 @@ void sde_evtlog_dump_all(struct sde_dbg_evtlog *evtlog)
 	char buf[SDE_EVTLOG_BUF_MAX];
 	bool update_last_entry = true;
 
-	if (!evtlog)
+	if (!evtlog || !(evtlog->dump_mode & SDE_DBG_DUMP_IN_LOG))
 		return;
 
 	while (sde_evtlog_dump_to_buffer(evtlog, buf, sizeof(buf),
@@ -230,6 +230,7 @@ struct sde_dbg_evtlog *sde_evtlog_init(void)
 
 	spin_lock_init(&evtlog->spin_lock);
 	evtlog->enable = SDE_EVTLOG_DEFAULT_ENABLE;
+	evtlog->dump_mode = SDE_DBG_DEFAULT_DUMP_MODE;
 
 	INIT_LIST_HEAD(&evtlog->filter_list);