helper/list: include the correct header file

The file 'list.h', copied from FreeBSD, does not depend from any
OpenOCD specific include file, but only needs 'stddef.h' for the
type 'size_t'.

Let 'list.h' to include the correct header file, then fix the now
broken dependencies in the other files that were incorrectly
relying on 'list.h' to include 'helper/types.h'

Change-Id: Idd31b5bf607e226cac44ef41b2aa335ae4dbf519
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8173
Tested-by: jenkins

src/helper/binarybuffer.h

@@ -11,7 +11,8 @@
 #ifndef OPENOCD_HELPER_BINARYBUFFER_H
 #define OPENOCD_HELPER_BINARYBUFFER_H
 
-#include "list.h"
+#include <helper/list.h>
+#include <helper/types.h>
 
 /** @file
  * Support functions to access arbitrary bits in a byte array

src/helper/list.h

@@ -35,7 +35,7 @@
 
 /* begin OpenOCD changes */
 
-#include <helper/types.h>
+#include <stddef.h>
 
 struct list_head {
 	struct list_head *next;

src/target/target.h

@@ -23,6 +23,7 @@
 #include <helper/list.h>
 #include "helper/replacements.h"
 #include "helper/system.h"
+#include <helper/types.h>
 #include <jim.h>
 
 struct reg;