Update git submodules

* Update docs/submodules/releng from branch 'master'
  to f6f325b5da12e258b32ae82c8b5e8c8a25620ccd
  - Merge "add release-notes link for stor4nfv"
  - add release-notes link for stor4nfv

    Change-Id: I581d3bf7b87e41a5534242bd573676b0c8e19127
    Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index dcc85bb..f6f325b 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit dcc85bb57ef9c5740dfbec5e0eda9c00c0d9ff47
+Subproject commit f6f325b5da12e258b32ae82c8b5e8c8a25620ccd