Add UDP bearer options to netlink bearer get message. This is used by
the tipc user space tool to display UDP options.

The UDP bearer information is passed using either a sockaddr_in or
sockaddr_in6 structs. This means the user space receiver should
intermediately store the retrieved data in a large enough struct
(sockaddr_strage) before casting to the proper IP version type.
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>