Update git submodules

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

    Change-Id: I47ae73da7240ee4c4e3902baa7320412a28ada6c
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 6d0f2fc..d6bb024 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 6d0f2fc0e6263478d87ce944846b540cbe896a3a
+Subproject commit d6bb024093f9c8427eaf966a4711d376997deb50