Update git submodules

* Update docs/submodules/clover from branch 'stable/fraser'
  - Simplification of Clover Fraser official docs

    (Double commit from master:I89adbef74aa74071a055dcdf62aa0925e263ffe3,
    gerrit 56167)

    Change-Id: I45071c2d7f3e4264596b9fbe5d8e086e3842fe37
    Signed-off-by: Stephen Wong <stephen.kf.wong@gmail.com>

diff --git a/docs/submodules/clover b/docs/submodules/clover
index 8d8abe2..4502257 160000 (submodule)
--- a/docs/submodules/clover
+++ b/docs/submodules/clover
@@ -1 +1 @@
-Subproject commit 8d8abe26ba133345213b4afaca729659ad81c385
+Subproject commit 4502257eefd9654f7ea8279f753b2b9be1c8ddd5