Remove linux/reboot.h

* linux/reboot.h: Remove.
* Makefile.am (EXTRA_DIST): Remove it.
* reboot.c: Do not include <linux/reboot.h>.
* xlat/bootflags1.in: Add default values.
* xlat/bootflags2.in: Likewise.
* xlat/bootflags3.in: Likewise.
diff --git a/xlat/bootflags1.in b/xlat/bootflags1.in
index d2b5f9f..4204823 100644
--- a/xlat/bootflags1.in
+++ b/xlat/bootflags1.in
@@ -1 +1 @@
-LINUX_REBOOT_MAGIC1
+LINUX_REBOOT_MAGIC1 0xfee1dead