drm/etnaviv: replace header include with forward declaration

The etnaviv_gpu header only needs to know about the pointer types, so
replace by a forward declaration and only include the headers where needed.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>

drivers/gpu/drm/etnaviv/etnaviv_gpu.c

@@ -3,10 +3,12 @@
  * Copyright (C) 2015-2018 Etnaviv Project
  */
 
+#include <linux/clk.h>
 #include <linux/component.h>
 #include <linux/dma-fence.h>
 #include <linux/moduleparam.h>
 #include <linux/of_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/thermal.h>
 
 #include "etnaviv_cmdbuf.h"

drivers/gpu/drm/etnaviv/etnaviv_gpu.h

@@ -6,9 +6,6 @@
 #ifndef __ETNAVIV_GPU_H__
 #define __ETNAVIV_GPU_H__
 
-#include <linux/clk.h>
-#include <linux/regulator/consumer.h>
-
 #include "etnaviv_cmdbuf.h"
 #include "etnaviv_drv.h"
 
@@ -88,6 +85,8 @@ struct etnaviv_event {
 
 struct etnaviv_cmdbuf_suballoc;
 struct etnaviv_cmdbuf;
+struct regulator;
+struct clk;
 
 #define ETNA_NR_EVENTS 30