Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Jobs on Compass built time out"
  - Jobs on Compass built time out

    In order to save the time, just download ubuntu and cirros images once and
    stored in the host for all dovetail jobs.

    JIRA: DOVETAIL-491

    Change-Id: I07b39d5a04bfbce9ebf43f184103b503785b6e7a
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index eabeb68..e7a2f01 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit eabeb68cdd73b39bfd9f1cd9e5283b7cbf874592
+Subproject commit e7a2f01bfcc13a1a51c0863ea37238702945d84a