Update git submodules

* Update docs/submodules/clover from branch 'stable/gambia'
  - Merge "Initial commit for Clovisor design doc" into stable/gambia
  - Initial commit for Clovisor design doc

    Change-Id: I9e878b0302623266a7c900f5ca53825d7a3492c3
    Signed-off-by: Stephen Wong <stephen.kf.wong@gmail.com>

diff --git a/docs/submodules/clover b/docs/submodules/clover
index 627bcd6..8ef9223 160000 (submodule)
--- a/docs/submodules/clover
+++ b/docs/submodules/clover
@@ -1 +1 @@
-Subproject commit 627bcd67358efaffe050e5e426093f2ea7233db0
+Subproject commit 8ef9223828fd5c2c7df7e29a5965af8040ded377