Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge changes from topics 'prototypes/xci/config/pinned-versions-bump-dates', 'prototypes/xci/config/pinned-versions-bump-bifrost-version'

    * changes:
      prototypes: xci: scripts: Update SHA dates
      prototypes: xci: update-osa-version-files: Add support for updating bifrost SHAs

  - prototypes: xci: scripts: Update SHA dates

    Update the dates in the pinned-versions file whenever we update
    the SHAs.

    Change-Id: I23ebd90a3fc688a7501fcb2d32217357f8c31657
    Signed-off-by: Markos Chandras <mchandras@suse.de>
  - prototypes: xci: update-osa-version-files: Add support for updating bifrost SHAs

    Add a second optional argument to update the bifrost SHA instead of
    doing this bit manually.

    Change-Id: I0fab8745ae08ad4f54a2a1f5b0b7a64fde4b8295
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index e858613..c5643ad 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit e858613f52f1d8b9bea04870921395d36055bfe6
+Subproject commit c5643adaaf9f4dd67b4adc617e00b25f8464d26a