IPVS: Backup, Adding structs for new sync format

New structs defined for version 1 of sync.

 * ip_vs_sync_v4       Ipv4 base format struct
 * ip_vs_sync_v6       Ipv6 base format struct

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>