Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Ignore All Changes to non-XCI Directories

    We only care to trigger builds based on changes under xci/, not
    including xci/README.rst

    Change-Id: I347e0d7ef658c41322b7c3e25740fa4d2f960bdc
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index f597985..a199806 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit f597985c58f77eeed32fbcbcafd98de51390dcee
+Subproject commit a199806d77fc35744a3222be208302b4da825d2b