ANDROID: dma-buf: heaps: Minor cleanup of dmabuf_page_pool includes

Remove the unused freezer, slab, device, and kref includes.
Move shrinker include to implementation file.
Fix dmabuf_page_pool documentation.

Fixes: 060e38dce1 ("ANDROID: dma-buf: heaps: replace mutex lock with spinlock")
Fixes: cc46bc6803 ("ANDROID: dma-buf: heaps: Add a shrinker controlled page pool")
Change-Id: Ie9ee58a02740c7833e60aed8a491b88d14c366e3
Signed-off-by: T.J. Mercier <tjmercier@google.com>

drivers/dma-buf/heaps/page_pool.c

@@ -8,12 +8,13 @@
  * Copyright (C) 2011 Google, Inc.
  */
 
-#include <linux/freezer.h>
+#include "page_pool.h"
+
 #include <linux/list.h>
-#include <linux/slab.h>
+#include <linux/shrinker.h>
+#include <linux/spinlock.h>
 #include <linux/swap.h>
 #include <linux/sched/signal.h>
-#include "page_pool.h"
 
 static LIST_HEAD(pool_list);
 static DEFINE_MUTEX(pool_list_lock);

drivers/dma-buf/heaps/page_pool.h

@@ -10,11 +10,8 @@
 #ifndef _DMABUF_PAGE_POOL_H
 #define _DMABUF_PAGE_POOL_H
 
-#include <linux/device.h>
-#include <linux/kref.h>
 #include <linux/mm_types.h>
-#include <linux/spinlock.h>
-#include <linux/shrinker.h>
+#include <linux/spinlock_types.h>
 #include <linux/types.h>
 
 /* page types we track in the pool */
@@ -29,7 +26,7 @@ enum {
  * struct dmabuf_page_pool - pagepool struct
  * @count[]:		array of number of pages of that type in the pool
  * @items[]:		array of list of pages of the specific type
- * @mutex:		lock protecting this struct and especially the count
+ * @lock:		lock protecting this struct and especially the count
  *			item list
  * @gfp_mask:		gfp_mask to use from alloc
  * @order:		order of pages in the pool