Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "[yardstick] add Ross to email recipients"
  - [yardstick] add Ross to email recipients

    as yardstick PTL I'd like to get Jenkins results emails

    Change-Id: If053ab72902c145a13e0dc965ff69211f33c4a88
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 06a9d73..81ffdba 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 06a9d7383889fbd8f4d1351ae6c9908fd1f248b6
+Subproject commit 81ffdba23f5b1c44c3431dd8670965234b0300d7