ss: usage: add missing parameters

ss: usage: add missing parameters

These query entries were in the man page but not in 'ss -h':

- packet_raw
- packet_dgram
- dccp
- sctp
- xdp (+ the --xdp option)

I only created one commit with all: this fixes multiple commits but all
on the same line.

The only exception is with '--xdp' parameter which is linked to
commit 2abc3d76 ("ss: add AF_XDP support").

Fixes: aba5acdf ("(Logical change 1.3)") # packet raw/dgram
Fixes: 351efcde ("Update header files to 2.6.14") # dccp
Fixes: f89d46ad ("ss: Add support for SCTP protocol") # sctp
Fixes: 2abc3d76 ("ss: add AF_XDP support") # xdp
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>