Update git submodules

* Update docs/submodules/sfc from branch 'master'
  - Merge "Enable local documentation builds"
  - Enable local documentation builds

    Adds a local conf.py and conf.yaml (using lfdocs-conf), to enable local
    docs build.

    Change-Id: Iaab750983f02476d9bccb6c9bcf2b38544d54d8c
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/sfc b/docs/submodules/sfc
index 853b855..77dfb2e 160000 (submodule)
--- a/docs/submodules/sfc
+++ b/docs/submodules/sfc
@@ -1 +1 @@
-Subproject commit 853b855803dd70bbc371e96fa8582cd0e039db04
+Subproject commit 77dfb2e6eb0f3c872ec25cc6196d13b5ddfe0a3b