Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "[yardstick] Add stable/fraser branch"
  - [yardstick] Add stable/fraser branch

    Change-Id: I6e682277b4447ecdc2fc30042ccf4c2b49a4d339
    Signed-off-by: Emma Foley <emma.l.foley@intel.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index c7177a0..57a678f 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit c7177a0024af425493b35febd16b6bc0462836d2
+Subproject commit 57a678f0bf28eecfcd02c2a4905b2c553bb6315e