Update docs for building ovs-dpdk images

Correcting and clarifying the documention for how to build OVS images
with DPDK support:

 * The additional heading was confusing and the following sentence even
   more so.
 * Fixed the image name in the build command.
 * Updated the OVS and DPDK version numbers to current stable versions.

Change-Id: Ib12be3da4f1fc14f1fed990a8abcdf87477a4e1b

doc/source/admin/template-override/ovs-dpdk.rst

@@ -9,30 +9,26 @@ To use the uio_pci_generic driver on Ubuntu a source build is required.
 Building ovs with dpdk containers from source
 ---------------------------------------------
 
-- Append the following to ``/etc/kolla/kolla-build.conf`` to select the version
-  of ovs and dpdk to use for your source build.
-
-kolla-build.conf
-________________
-
-In this place the ``contrib/template-override/ovs-dpdk.j2`` file:
+Append the following to ``/etc/kolla/kolla-build.conf`` to select the version
+of ovs and dpdk to use for your source build.
 
 .. code-block:: console
 
    [openvswitch-base-plugin-ovs]
    type = git
    location = https://github.com/openvswitch/ovs.git
-   reference = v2.7.0
+   reference = v2.10.0
 
    [openvswitch-base-plugin-dpdk]
    type = git
    location = http://dpdk.org/git/dpdk
-   reference = v17.02
+   reference = v17.11
 
-To build the container execute the follow command:
+
+To build the container, run the following command inside a cloned kolla
+repository:
 
 .. code-block:: console
 
-   tools/build.py --template-override \
-   contrib/template-override/ovs-dpdk.j2 dpdk
+   tools/build.py -t source --template-override contrib/template-override/ovs-dpdk.j2 ovsdpdk