dm: use list_count_nodes() for counting list nodes

The linux kernel has the list_count_nodes() API functions which is
used for counting nodes of a list. This has now been imported in
U-Boot as part of an earlier commit. Use this function and drop the
list_count_items().

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

drivers/core/util.c

@@ -3,23 +3,13 @@
  * Copyright (c) 2013 Google, Inc
  */
 
+#include <vsprintf.h>
 #include <dm/device.h>
 #include <dm/ofnode.h>
 #include <dm/read.h>
 #include <dm/util.h>
 #include <linux/libfdt.h>
-#include <vsprintf.h>
-
-int list_count_items(struct list_head *head)
-{
-	struct list_head *node;
-	int count = 0;
-
-	list_for_each(node, head)
-		count++;
-
-	return count;
-}
+#include <linux/list.h>
 
 #if CONFIG_IS_ENABLED(OF_REAL)
 int pci_get_devfn(struct udevice *dev)