Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Restrict functest running with k8 deployment

    Also, improve suite job with alpine images.

    Change-Id: I1367dea6b09361641c38ef91652acec5be4fbebb
    Signed-off-by: Linda Wang <wangwulin@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 709f567..78f4ee9 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 709f56704f29a943abc7b4a339b4d184270a2420
+Subproject commit 78f4ee940f970ebcf2e9d76c4f0013c0cbf61bb4