sctp: add sctp/remaddr table to complete RFC remote address table OID

Add support for RFC3873 remote address table OID.

      +--(5) sctpAssocRemAddrTable
      |   |
      |   |--(-) sctpAssocId (shared index)
      |   |
      |   +--(1) sctpAssocRemAddrType (index)
      .   |
      .   +--(2) sctpAssocRemAddr (index)
      .   |
          +--(3) sctpAssocRemAddrActive
          |
          +--(4) sctpAssocRemAddrHBActive
          |
          +--(5) sctpAssocRemAddrRTO
          |
          +--(6) sctpAssocRemAddrMaxPathRtx
          |
          +--(7) sctpAssocRemAddrRtx
          |
          +--(8) sctpAssocRemAddrStartTime

This patch places all the requsite data in /proc/net/sctp/remaddr.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>