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

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

SPDX: license IDs for some ISC-related files.

bhnd(4): extend the PMU APIs to support bwn(4)

The bwn(4) driver requires a number of extensions to the bhnd(4) PMU
interface to support external configuration of PLLs, LDOs, and other
parameters that require chipset or PHY-specific workarounds.

These changes add support for:

- Writing raw voltage register values to PHY-specific LDO regulator
registers (required by LP-PHY).
- Enabling/disabling PHY-specific LDOs (required by LP-PHY)
- Writing to arbitrary PMU chipctrl registers (required for common PHY PLL
reset support).
- Requesting chipset/PLL-specific spurious signal avoidance modes.
- Querying clock frequency and latency.

Additionally, rather than updating legacy PWRCTL support to conform to the
new PMU interface:

- PWRCTL API is now provided by a bhnd_pwrctl_if.m interface.
- Since PWRCTL is only found in older SSB-based chipsets, translation from
bhnd(4) bus APIs to corresponding PWRCTL operations is now handled
entirely within the siba(4) driver.
- The PWRCTL-specific host bridge clock gating APIs in bhnd_bus_if.m have
been lifted out into a standalone bhnd_pwrctl_hostb_if.m interface.

Approved by: adrian (mentor, implicit)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D12664

bhnd: Add support for supplying bus I/O callbacks when initializing an EROM
parser.

This allows us to use the EROM parser API in cases where the standard bus
space I/O APIs are unsuitable. In particular, this will allow us to parse
the device enumeration table directly from bhndb(4) drivers, prior to
full attach and configuration of the bridge.

Approved by: adrian (mentor)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D12510

Bring over the initial rewrite of the broadcom bus support found in their
SoCs and various chips (including, famously, their wifi chips.)

This is "just" (all 20,000 lines of it) code to enumerate the various
versions of busses inside these devices, including the PCI bridge and
the direct SIBA bridge found in MIPS chips.

It also includes shared code for some bus operations (suspend, resume, etc);
EEPROM/SROM/etc parsing and other things that are shared between chips.

Eventually this'll replace the code that bwi/bwn uses for the internal
bus, as well as some apparently upcoming mips74k broadcom SoC support
which uses bwn!

Thanks to Landon Fuller <landonf@landonf.org> for all this work!

Obtained from: https://github.com/landonf/freebsd/compare/user/landonf/bcm4331-CURRENT