bnxt: Report SR-IOV VF status

[kbowling]

Summary

Expose the PF-known effective per-VF MAC, allocated transmit and receive
queue counts, and policy state through the iflib VF status method.
Snapshot the state under the SR-IOV lock so concurrent trust and
anti-spoof sysctl updates cannot produce a torn report.  Mark known queue
allocations present even when their value is zero.

Cache a VF-selected MAC only after firmware accepts the forwarded
request.  Prefer that address in status.  Replay the accepted address,
trust state, and MAC anti-spoof policy after firmware recovery.

Record completion of the per-VF configuration callback separately from
firmware resource allocation.

Track successful PCI SR-IOV attachment independently of the active VF
count.  This lets a supported but unconfigured PF return an empty status
while unsupported devices and failed attachments omit it.

Test Plan

I don't have HW, can you route to the right Broadcom folks?

[kbowling]

This is a basic implementation, someone more familiar with the driver may look at the nvlist schema and https://reviews.freebsd.org/D58739 which demonstrates driver extensions.

[kbowling]

Update to committed netlink API

[kbowling]

Use BNXT_SRIOV_LOCK around MAC ops