Update git submodules

* Update docs/submodules/clover from branch 'stable/fraser'
  - Update yaml manifests for Fraser release tag

    - Updated the SDC toplevel manifest to use the 'opnfv-6.0.0' tag
    - Updated the yaml rendering scripts for individual services
    under snort/nginx to use opnfv docker images

    Change-Id: I90ef2a8ff5fcc47076192cb556a3a0ff3a9bd846
    Signed-off-by: Eddie Arrage <eddie.arrage@huawei.com>

diff --git a/docs/submodules/clover b/docs/submodules/clover
index aae68d3..2fca211 160000 (submodule)
--- a/docs/submodules/clover
+++ b/docs/submodules/clover
@@ -1 +1 @@
-Subproject commit aae68d3d9dbb8baa3cadef134e6e045ad79f1f57
+Subproject commit 2fca21164f3ad88f1ab2d31183966102cb3805a0