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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

ipq4018: add initial IPQ4018/IPQ4019 support

This is for the Qualcomm Atheros quad-core ARMv7 SoC with built-in
2x2 2GHz and 5GHz ath10k devices.

It's enough (with an upcoming set of config files) to netboot
on an ASUS router I have here and get to a single core mountroot
prompt.