Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Fix Docker Container Build Tagging"
  - Fix Docker Container Build Tagging

    Builds triggered by tags have a typo in the extraction of the tag name.
    This change includes a method for retriggering a tag build with the
    comment "retag TAG_NAME".

    Change-Id: Ie035e0922f8c073d3e360917ea7ccd6fa76d7b20
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 03ffe53..8b08871 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 03ffe53f51867bfc21d025f50edce3370937830f
+Subproject commit 8b0887127cadeebadff89af51eede98ca69edc20