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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

[PPC64] Initial libkvm minidump implementation

This change adds PowerPC64 support for minidumps on libkvm.

Address translation, page walk, and data retrieval were tested and seem to be
working correctly.

Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D21555