Update git submodules

* Update docs/submodules/samplevnf from branch 'master'
  - Merge "Add l3 support for tasks without physical tx ports"
  - Add l3 support for tasks without physical tx ports

    This adds support for tasks in l3 submode receiving from ports but
    transmitting to rings.

    ARP related information is exchanged between tasks through master core.
    Tasks transmitting to physical ports are responsible to transmit arp
    related packets. Tasks not transmitting to physical ports (and using
    rings) should not try to transmit arp packets. Transmitting arp
    packets through ring would be more complex, as we would need extra information
    (within the mbuf) to distinguish for instance an arp reply comoing from the
    network and an arp reply coming from a core (as a reply to an arp request).

    Change-Id: Ib55dc8c39d5e55703a933faa16bcc008f1274929
    Signed-off-by: Xavier Simonart <xavier.simonart@intel.com>

diff --git a/docs/submodules/samplevnf b/docs/submodules/samplevnf
index 516310e..6401ebd 160000 (submodule)
--- a/docs/submodules/samplevnf
+++ b/docs/submodules/samplevnf
@@ -1 +1 @@
-Subproject commit 516310e780f11d844bc06e5fafb60938e329c651
+Subproject commit 6401ebd2b472a2402b640f4e8c773cc3d097093f