Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "bifrost: Optimize the OPNFV bifrost playbook"
  - bifrost: Optimize the OPNFV bifrost playbook

    We could combine several plays into a single one when they are executed
    to the same set of nodes. This has the added benefit that we avoid all
    the Ansible warm-up operations when a new play is started.

    Change-Id: Ibcad07d1b74f1d7cc5a9c60e4b2a6130fb6178fd
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng-xci b/docs/submodules/releng-xci
index 665a9e0..941bfd7 160000 (submodule)
--- a/docs/submodules/releng-xci
+++ b/docs/submodules/releng-xci
@@ -1 +1 @@
-Subproject commit 665a9e08c658e5b851416f4f282520a338cd4d49
+Subproject commit 941bfd7be7cf37f33a2b4f821bbb869e25ebcfd2