uboot-lantiq: fix compile with modern host dtc

In dtc version 1.4.6 the macro names in header include guards changed,
but the build relies on them matching in order to replace selected
headers. This is a horrible hack to work around this.

Signed-off-by: Thomas Nixon <tom@tomn.co.uk>

package/boot/uboot-lantiq/patches/200-fix-dtc-header-guard.patch

@@ -0,0 +1,19 @@
+--- a/include/libfdt_env.h
++++ b/include/libfdt_env.h
+@@ -8,6 +8,7 @@
+
+ #ifndef _LIBFDT_ENV_H
+ #define _LIBFDT_ENV_H
++#define LIBFDT_ENV_H
+
+ #include "compiler.h"
+ #include "linux/types.h"
+--- a/include/libfdt.h
++++ b/include/libfdt.h
+@@ -1,5 +1,6 @@
+ #ifndef _LIBFDT_H
+ #define _LIBFDT_H
++#define LIBFDT_H
+ /*
+  * libfdt - Flat Device Tree manipulation
+  * Copyright (C) 2006 David Gibson, IBM Corporation.