Update git submodules

* Update docs/submodules/releng from branch 'master'
  to eac9401eae653ecef9749a31b67c28110de73688
  - Merge "Switch to lf-build2"
  - Switch to lf-build2

    There is no slave called intel-pod15.

    Change-Id: Ib03ef798ac117090f408ca9d562a6efc09e48340
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 991cb81..eac9401 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 991cb8180af6183bcc30c5585dd0788fe3c9ee5f
+Subproject commit eac9401eae653ecef9749a31b67c28110de73688