Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Add unit tests for copper

    Change-Id: Ia4e53e2aee5b93071b3acd3d75c7e42841321a0a
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 98edab9..4db57a5 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 98edab949da9fcce193acc9b66546b7b2fd77d7c
+Subproject commit 4db57a5fa786e9e209b428d4215b6033d15f1315