Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "xci: Start developer documentation"
  - xci: Start developer documentation

    Change-Id: Ib5200372a44ee6a22b45c2105b3729d362eacb1d
    Signed-off-by: Fatih Degirmenci <fatih.degirmenci@ericsson.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 88395f5..4f6a549 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 88395f5f3a5b4c5b41451fbff6a69ecba05a5e20
+Subproject commit 4f6a549044da900b0cc785f442bffa8120a12dc0