Move CLIP table handling out of TOM and into the base driver.

[jhb]

Summary

• Store the clip table in 'struct adapter' instead of in the TOM softc.
• Init the clip table during attach and teardown during detach.
• While here, add a dev.<nexus>.<unit>.misc.clip sysctl to dump the CLIP table.

This does mean that we update the clip table even if TOE is not enabled,
but non-TOE things need the CLIP table anyway.

Test Plan

• Tested using TOE+TLS over IPv6 and IPv4.
• Also used in the inline TLS branch.

[jhb]

Sample output:

# sysctl -n dev.t6nex.0.misc.clip
IP address                               Users
fe80::1                                      0
fe80::207:43ff:fe2c:2cd0                     0
10::161:31                                   0
fe80::207:43ff:fe04:b650                     0
10:1::161:31                                 8

sys/dev/cxgbe/t4_clip.c

371 ↗

(On Diff #50498)

To simplify the patch this still uses a single task which then has to use t4_iterate, etc. We could instead have a per-adapter task that only runs when new interfaces are added on a Chelsio adapter by storing the 'struct task' in the adapter and the and event handler tag in the ifp->if_softc and then passing the 'ifp' instead of NULL when calling EVENTHANDLER_REGISTER. The handler could then do 'if arg == ifp' and then use ifp_softc to find the vi_info, etc. This would remove the need for t4_iterate and the racy mtx_initialized check.

[krishna2_chelsio.com]

Reviewed, code changes look good to me.