Update git submodules

* Update docs/submodules/releng from branch 'master'
  - functest: Enable jobs per stream

    Change-Id: I5289fedf52354f2cef6a3202df27d35acccb7c6c
    Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index e21c707..39291cb 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit e21c70758705d45db40f5536f0b15db463b7e207
+Subproject commit 39291cb28712046f1c4e0ac107a67b582f3fa664