sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

vmm: Pass vcpu instead of vm and vcpuid to APIs used from CPU backends.

Reviewed by: corvink, markj
Differential Revision: https://reviews.freebsd.org/D37162

vmm: Refactor storage of CPU-dependent per-vCPU data.

Rather than storing static arrays of per-vCPU data in the CPU-specific
per-VM structure, adopt a more dynamic model similar to that used to
manage CPU-specific per-VM data.

That is, add new vmmops methods to init and cleanup a single vCPU.
The init method returns a pointer that is stored in 'struct vcpu' as a
cookie pointer. This cookie pointer is now passed to other vmmops
callbacks in place of the integer index. The index is now only used
in KTR traces and when calling back into the CPU-independent layer.

Reviewed by: corvink, markj
Differential Revision: https://reviews.freebsd.org/D37151

Add SPDX tags to vmm(4).

MFC after: 4 weeks.
Sponsored by: iXsystems Inc.

Remove unused header file.

Discussed with: Anish Gupta (akgupt3@gmail.com)

Add in last remaining files to get AMD-SVM operational.

Submitted by: Anish Gupta (akgupt3@gmail.com)