Merge branch 'net-erspan-add-support-for-openvswitch'

William Tu says:

====================
net: erspan: add support for openvswitch

The first patch refactors the erspan header definitions.
Originally, the erspan fields are defined as a group into a __be16 field,
and use mask and offset to access each field.  This is more costly due to
calling ntohs/htons and error-prone.  The first patch changes it to use
bitfields.  The second patch creates erspan.h in UAPI and move the definition
'struct erspan_metadata' to it for later openvswitch to use.  The final patch
introduces the new OVS tunnel key attribute, OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS,
to program both v1 and v2 erspan tunnel for openvswitch.
====================

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