Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Build euphrates iso for deploy

    Change-Id: I68e3caede7b209a7d1afe9ea46e49686daf83147
    Signed-off-by: wutianwei <wutianwei1@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 426fd86..9bcae9e 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 426fd8603c24d0fdb5cc019f2aea6080ddba6744
+Subproject commit 9bcae9eb3764664cdfc800ca361342c6c0b7cde3