Merge branch 'ovs-gre'

Pravin B Shelar says:

====================
GRE: Use flow based tunneling for OVS GRE vport.

Following patches make use of new Using GRE tunnel meta data
collection feature. This allows us to directly use netdev
based GRE tunnel implementation. While doing so I have
removed GRE demux API which were targeted for OVS. Most
of GRE protocol code is now consolidated in ip_gre module.

v5-v4:
Fixed Kconfig dependency for vport-gre module.

v3-v4:
Added interface to ip-gre device to enable meta data collection.
While doing this I split second patch into two patches.

v2-v3:
Add API to create GRE flow based device.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>