tunneling: Vanilla OVS decapsulation tests

tunneling: Vanilla OVS decapsulation tests

Add Vanilla OVS VXLAN/GRE/GENEVE decapsulation tests
Recent changes:
* Line wrap
* Fix GENEVE IP settings
* Add GRE and GENEVE steps to integration.rst
* Add DUT_NIC1_MAC and DUT_NIC2_MAC
* Remove unnecessary call to vswitch.set_tunnel_arp
* Move optional VXLAN/GRE/GENEVE decap settings to a different section
* Add tunnel type to report files md and rst
* Fix typo error: l4 to L4 in conf/integration/03_traffic.conf

Change-Id: I8a43521668d5870ec893aed1df49467f0a84a07d
JIRA: VSPERF-180
Signed-off-by: Dino Simeon Madarang <dino.simeonx.madarang@intel.com>
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Brian Castelli <brian.castelli@spirent.com>