The VMADDR_CID_RESERVED (1) was used by VMCI, but now it is not
used anymore, so we can reuse it for local communication
(loopback) adding the new well-know CID: VMADDR_CID_LOCAL.
Cc: Jorgen Hansen <jhansen@vmware.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Jorgen Hansen <jhansen@vmware.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>