Update git submodules

* Update docs/submodules/releng from branch 'master'
  to a881bf7e7834d38771c9d26f84500a3ade49bec4
  - Remove all kube_bench exclusions

    It has been backported in all branches.

    Change-Id: I81e6ed3acce74cffdcd98a67717f2e44553df760
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 662629d..a881bf7 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 662629d5871bc1e55c362291fda2fc8be6ae72ee
+Subproject commit a881bf7e7834d38771c9d26f84500a3ade49bec4