sctp: remove the typedef sctp_param_t

This patch is to remove the typedef sctp_param_t, and replace with
struct sctp_paramhdr in the places where it's using this typedef.

It is also to remove the useless declaration sctp_addip_addr_config
and fix the lack of params for some other functions' declaration.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>