Update git submodules

* Update docs/submodules/functest from branch 'master'
  - bug fix download_images.sh

    when xz the downloaded file, if the uncompressed target file already exists
    it exits with status 1 and breaks the gate

    Change-Id: Ie97ff34e6522af48c799e7c8c97dc3310222e683
    Signed-off-by: Morgan Richomme <morgan.richomme@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 4d944e5..bc25ad7 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 4d944e52db2c2a39d2417006a9945b949170a916
+Subproject commit bc25ad7ad1a9299a07aca77bd9207342711f4bd9