Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "reporting adoption for Euphrates"
  - reporting adoption for Euphrates

    Danube -> Euphrates in euphrates.html
    add euphrates dir
    fix CONFIG_REPORTING_YAML value
    fix import error in scenario.py

    Change-Id: Ic0457bf8d1c67bd21ef6a31564792eb98cfca9ad
    Signed-off-by: chenjiankun <chenjiankun1@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 2461f04..4ba227e 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 2461f04429ade8ec5046e9a0d77cdd11db11e75b
+Subproject commit 4ba227e8fcd2a5e20bb04ecf9cbc7779f8039f32