Update git submodules

* Update docs/submodules/releng from branch 'master'
  - [fuel, armband] Switch CI jobs to gambia

    - keep fraser jobs for Dovetail, schedule 4 CI runs / week / arch;
    - stop running Functest/Yardstick for fraser to cut down CI time;
    - reschedule master/gambia triggers to ensure an uniform CI POD
      allocation across the week;
    - enable gambia triggers;

    Change-Id: I2a66628ff3525cc9cbd4ffbb4b790633257b6cba
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 946e6ef..2ac6d92 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 946e6ef7957ad50904f52d6fdf5d1981eb00d643
+Subproject commit 2ac6d92e3e7aa87ad3eaa0eca9c2cc78466753c5