openvswitch: Enable tunnel GSO for OVS bridge.

Following patch enables all available tunnel GSO features for OVS
bridge device so that ovs can use hardware offloads available to
underling device.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>

diff --cc include/linux/netdev_features.h
Simple merge

diff --cc net/openvswitch/vport-internal_dev.c
Simple merge