Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "jjb: xci: Fix bifrost blockers for XCI jobs"
  - jjb: xci: Fix bifrost blockers for XCI jobs

    The bifrost regexp was wrong leading to conflicts betwen the XCI
    and bifrost jobs. Moreover, we need to add the same restrictions for
    jobs/node on bifrost jobs similar to the XCI ones. This finally fixes
    the 'throttle' property to use the 'xci-verify-virtual' category.

    Change-Id: I6d3f8fdd82738c1d079b1a3fdef134753eb4281a
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 437eb58..c87c17a 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 437eb58c06f204baabdb3abc47c1956794b649e0
+Subproject commit c87c17ab156cd9f7fe60f4adc5ee893b99096dd7