Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Fix missing python packages for password generation"
  - Fix missing python packages for password generation

    These packages are needed by pw-token-gen.py tool

    Change-Id: Ib9d165274449551a469e201da9feeffac5a7a4cf
    Signed-off-by: Juan Vidal Allende <juan.vidal.allende@ericsson.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 1dea2ca..3bd556d 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 1dea2cad906da7da95ccd84f96ed49429e2b9c3d
+Subproject commit 3bd556d74c6e75da6c54781d410303dbb75fb9a4