[PATCH] ppc64: Squash warning in ppc64 addnote tool

From: David Gibson <david@gibson.dropbear.id.au>

addnote in arch/ppc64/boot (a userspace tool, not kernel code) uses exit()
without including stdlib.h.

arch/ppc64/boot/addnote.c

@@ -14,6 +14,7 @@
  * Usage: addnote zImage
  */
 #include <stdio.h>
+#include <stdlib.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <string.h>