Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Remove euphrates jobs"
  - Remove euphrates jobs

    Change-Id: I0a5a6d584b3740d88dc4f342ffc1d107962762e6
    Signed-off-by: agardner <agardner@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index c362875..d7f9cb9 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit c362875ea56b5dc1cacc69059e199d74668feeb5
+Subproject commit d7f9cb927085b4edf95e71d8c3e49007e3b03276