drm/etnaviv: clean up includes

Drop unused includes, move more includes from the generic etnaviv_drv.h to
the units where they are actually used, sort includes.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

drivers/gpu/drm/etnaviv/etnaviv_iommu.c

@@ -3,11 +3,11 @@
  * Copyright (C) 2014-2018 Etnaviv Project
  */
 
+#include <linux/bitops.h>
+#include <linux/dma-mapping.h>
 #include <linux/platform_device.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
-#include <linux/dma-mapping.h>
-#include <linux/bitops.h>
 
 #include "etnaviv_gpu.h"
 #include "etnaviv_mmu.h"