datapath: Add 'ovdk_vport_veth'

Add 'ovdk_vport_veth', which provides some helper functions for
initialising the KNI device underlayer of 'rte_port_veth' ports
as well as the 'rte_port_veth' ports themselves.

This implementation is heavily based around the implementation of
US-vHost included with Intel DPDK vSwitch.

Change-Id: I833e6d69287c867fd900617087fe6aab371999c6
Signed-off-by: Stephen Finucane <stephen.finucane@intel.com>
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Reviewed-by: Mark D. Gray <mark.d.gray@intel.com>
Reviewed-by: Meghan Halton <meghan.halton@intel.com>
Reviewed-by: Ian Stokes <ian.stokes@intel.com>
datapath: Integrate vEth code

Integrate the new vEth code such that vEths are initialied on startup
(as with every other port type) and are available from then on. In
summary:

- Add calls to the init functions for the vEth ports to 'ovdk_vport.c'
- Remove a duplication of the 'OVDK_MAX_MEMNICS' macro
- Add required entries to 'datapath/dpdk/automake.mk'
- Expand 'vport_kni' struct to include new parameters

Change-Id: I5be050363d576dfc202df8f3ae95b3e4c3f8a32d
Signed-off-by: Stephen Finucane <stephen.finucane@intel.com>
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Reviewed-by: Mark D. Gray <mark.d.gray@intel.com>
Reviewed-by: Meghan Halton <meghan.halton@intel.com>
Reviewed-by: Ian Stokes <ian.stokes@intel.com>
datapath: Fix typos in vhost devices

Change-Id: Ia2ad16723c8762a7eae6a22653a8df73af7c60f2
Signed-off-by: Stephen Finucane <stephen.finucane@intel.com>
Reviewed-by: Mark D. Gray <mark.d.gray@intel.com>
Reviewed-by: Meghan Halton <meghan.halton@intel.com>
Reviewed-by: Ian Stokes <ian.stokes@intel.com>
datapath: Remove non-existent MEMNIC vports

Change-Id: Ib5c8c98278841f47f48edc72527dbf73629fd226
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Reviewed-by: Mark D. Gray <mark.d.gray@intel.com>
Reviewed-by: Meghan Halton <meghan.halton@intel.com>
Reviewed-by: Ian Stokes <ian.stokes@intel.com>