Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Update xtesting version to 0.22.0

    Change-Id: I4dc3eb42d122986fb2ac131279aab57cdf92d916
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index ddc0e89..661fed2 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit ddc0e89d3d24d40267c31408cf9adf123d924c8f
+Subproject commit 661fed2fa81d70e145ce5290d243ab523d3d7fc1