kbuild: install kernel-page-flags.h

Programs using /proc/kpageflags need to know about the various flags.  The
<linux/kernel-page-flags.h> provides them and the comments in the file
indicate that it is supposed to be used by user-level code.  But the file
is not installed.

Install the headers and mark the unstable flags as out-of-bounds.  The
page-type tool is also adjusted to not duplicate the definitions

Signed-off-by: Ulrich Drepper <drepper@gmail.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kernel-page-flags.h b/include/linux/kernel-page-flags.h
index 26a6571..a1bdf69 100644
--- a/include/linux/kernel-page-flags.h
+++ b/include/linux/kernel-page-flags.h
@@ -32,6 +32,8 @@
 #define KPF_KSM			21
 #define KPF_THP			22
 
+#ifdef __KERNEL__
+
 /* kernel hacking assistances
  * WARNING: subject to change, never rely on them!
  */
@@ -44,4 +46,6 @@
 #define KPF_ARCH		38
 #define KPF_UNCACHED		39
 
+#endif /* __KERNEL__ */
+
 #endif /* LINUX_KERNEL_PAGE_FLAGS_H */