DM: cleanup for header inclusions

used https://gitlab.com/esr/deheader to detect and remove unnecessary
header file inclusions

Signed-off-by: Zide Chen <zide.chen@intel.com>

devicemodel/core/mem.c

@@ -32,16 +32,13 @@
  * so it can be searched within the range.
  */
 
-#include <sys/cdefs.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <stdbool.h>
 #include <assert.h>
 #include <pthread.h>
 
 #include "vmm.h"
-#include "types.h"
 #include "mem.h"
 #include "tree.h"