datapath: Account for new flags args of vxlan_sock_add()

The upstream commit 359a0ea
("vxlan: Add support for UDP checksums (v4 sending, v6 zero csums)")
has introduced a new flags argument to vxlan_sock_add().

OVS does not pass any flags at this point, thus specyfing 0 will be
compatible with both the old ipv6 bool and the new u32 flags argument.

Upstream: 359a0ea ("vxlan: Add support for UDP checksums (v4 sending, v6 zero csums)")
Signed-off-by: Thomas Graf <tgraf@noironetworks.com>
datapath: Account for VXLAN-GBP changes to VXLAN API

Allows compiling the datapath against a VXLAN-GBP enabled kernel
but does not enable the VXLAN-GBP extension itself yet.

The required changes include a new vxlan_xmit_skb() and vxlan_rcv()
variant which takes a vxlan_metadata argument instead of the VNI.
As well as a vxlan_sock_add() compatibility wrapper which understands
the new extension argument.

Signed-off-by: Thomas Graf <tgraf@noironetworks.com>
datapath: VXLAN Group Policy definitions

Signed-off-by: Thomas Graf <tgraf@noironetworks.com>
ovs: VXLAN Group Policy support

Signed-off-by: Madhu Challa <challa@noironetworks.com>