Update git submodules

* Update docs/submodules/apex from branch 'stable/danube'
  - Add support for interface role mapping for odl_l3-fdio scenarios

    JIRA: APEX-445
    opnfv-puppet-tripleo-pr: 24

    Change-Id: Idbb855badae2f2b91202961c12931ba54be1beaa
    Signed-off-by: Feng Pan <fpan@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index baaa7ac..d358ad2 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit baaa7ac3cdc7984c97a4e1873ad118969ba95a01
+Subproject commit d358ad2a8a0716aea05c0c509149663ac4fad9df