Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "xci: SHA bump as of September 5th 2017"
  - xci: SHA bump as of September 5th 2017

    The SHA bump is required for SUSE support.

    Change-Id: If21e7658ee2ee967c458c08d186b5c1d07b5d93c
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng-xci b/docs/submodules/releng-xci
index 8f252cd..6454ecc 160000 (submodule)
--- a/docs/submodules/releng-xci
+++ b/docs/submodules/releng-xci
@@ -1 +1 @@
-Subproject commit 8f252cda5440924a4dbd248c7ce097ab744c9ab2
+Subproject commit 6454eccb0a2dfd31baf454ab5fcc2dc3a2b8155d