Following patch adds vxlan vport type for openvswitch using
vxlan api. So now there is vxlan dependency for openvswitch.

CC: Jesse Gross <jesse@nicira.com>
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Acked-by: NJesse Gross <jesse@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>