if_bnxt: rework interrupt coalescing onto the AGGINT_QCAPS scheme

[sumit.saxena_broadcom.com]

Summary

Query firmware-advertised coalescing capabilities and program
per-direction rx/tx coalescing settings against them, replacing the
old hardcoded scheme. Add sysctls for the coalescing mode, budget,
and stats-timer knobs the new scheme exposes.

[gallatin]

sys/dev/bnxt/bnxt_en/bnxt_hwrm.c

3495

I think you need to explicitly take the hwrm lock and call the _hwrm_send_message() variant. As far as I can see, the resp is shared among commands and zeroed at every use, so once you drop the lock (which hwrm_send_message() does before return), the response could be zeroed or for somebody else's command.

[sumit.saxena_broadcom.com]

sys/dev/bnxt/bnxt_en/bnxt_hwrm.c

3495

Yes, need to take hwrm lock explicitly, will fix it up in v2.

[sumit.saxena_broadcom.com]

Handled review bugs/comments