Update git submodules

* Update docs/submodules/container4nfv from branch 'master'
  - Merge "rebase to k8s 1.12 & docker 18.06 and enable device plugin"
  - rebase to k8s 1.12 & docker 18.06 and enable device plugin

    Change-Id: Ifbe25c03de1c11144d093fe710b2a48c5c419b89
    Signed-off-by: Guo Ruijing <ruijing.guo@intel.com>

diff --git a/docs/submodules/container4nfv b/docs/submodules/container4nfv
index 236aac4..4782abb 160000 (submodule)
--- a/docs/submodules/container4nfv
+++ b/docs/submodules/container4nfv
@@ -1 +1 @@
-Subproject commit 236aac413e9d5731d6a76a475c6b5dd85bacf3ac
+Subproject commit 4782abb8492b88cde19bf11fac42d0f501fb5d31