upstream: Add $OpenBSD$ markers to xmss files to help keep synced

with portable. ok djm@.

OpenBSD-Commit-ID: 5233a27aafd1dfadad4b957225f95ae51eb365c1
diff --git a/xmss_fast.h b/xmss_fast.h
index 52a83f8..2ffba70 100644
--- a/xmss_fast.h
+++ b/xmss_fast.h
@@ -1,4 +1,5 @@
 #ifdef WITH_XMSS
+/* $OpenBSD: xmss_fast.h,v 1.2 2018/02/26 03:56:44 dtucker Exp $ */
 /*
 xmss_fast.h version 20160722
 Andreas Hülsing