Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Fraser Tagging: 6.2.0"
  - Fraser Tagging: 6.2.0

    vswitchperf tagging.

    Change-Id: I93a7d97e89d493b2ace9bf2c00b1932a89bab772
    Signed-off-by: Sridhar K. N. Rao <sridhar.rao@spirent.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 984791c..27a4d96 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 984791cdded07a3341b48fc768b2bfbf1cb7c26a
+Subproject commit 27a4d9698aa9c64716547b62c2cfbbbeba1e44eb