Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Putting the required  back

    This is required for StorPerf multi-arch and causes all the StorPerf
    ARM builds to fail if it is not present.

    Change-Id: I302c0471a52759cd9c051741e2b0bb086b87e8eb
    Signed-off-by: mbeierl <mark.beierl@dell.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index e8c25aa..6b5e80b 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit e8c25aaf9d1b59c0d4a47ad33ac9c6dc3208f003
+Subproject commit 6b5e80b0de5b166d7a790b219424c78b79221557