rcache/base: add missing file to tarball

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

opal/mca/rcache/base/Makefile.am

@@ -9,7 +9,7 @@
 #                         University of Stuttgart.  All rights reserved.
 # Copyright (c) 2004-2005 The Regents of the University of California.
 #                         All rights reserved.
-# Copyright (c) 2013-2015 Los Alamos National Security, LLC. All rights
+# Copyright (c) 2013-2016 Los Alamos National Security, LLC. All rights
 #                         reserved
 # $COPYRIGHT$
 #
@@ -31,3 +31,6 @@ libmca_rcache_la_SOURCES += \
 	base/rcache_base_vma.c \
 	base/rcache_base_vma_tree.c \
 	base/rcache_base_mem_cb.c
+
+dist_opaldata_DATA = \
+        base/help-rcache-base.txt