disp: msm: sde: check power event before set clk rate

Clock rate can be set from debugfs, and this can attempt to
set clock rate even when display power is not enabled.
Set clock rate should check the last power event first.

Change-Id: Ibf01753a288e5a3003928664c99aa6dbf26350d6
Signed-off-by: Nilaan Gunabalachandran <ngunabal@codeaurora.org>

msm/sde_power_handle.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2016-2019, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2016-2020, The Linux Foundation. All rights reserved.
  */
 
 #ifndef _SDE_POWER_HANDLE_H_
@@ -154,6 +154,7 @@ struct sde_power_handle {
 	struct sde_power_data_bus_handle data_bus_handle
 		[SDE_POWER_HANDLE_DBUS_ID_MAX];
 	struct list_head event_list;
+	u32 last_event_handled;
 	struct sde_rsc_client *rsc_client;
 	bool rsc_client_init;
 };