Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "create stable/fraser branch for stor4nfv"
  - create stable/fraser branch for stor4nfv

    Change-Id: I5f7cb8fdced619b44124ad71e3d5f7104a9cf35c
    Signed-off-by: Guo Ruijing <ruijing.guo@intel.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 0f17f10..48af0c1 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 0f17f106681a159e9dbf7a1e06d33f4ab6618eb6
+Subproject commit 48af0c1b21362947981aca3d67eb781c1d68d2d6