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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

SPDX: license IDs for some ISC-related files.

- Allow different slicers for different flash types to be registered
with geom_flashmap(4) and teach it about MMC for slicing enhanced
user data area partitions. The FDT slicer still is the default for
CFI, NAND and SPI flash on FDT-enabled platforms.
- In addition to a device_t, also pass the name of the GEOM provider
in question to the slicers as a single device may provide more than
provider.
- Build a geom_flashmap.ko.
- Use MODULE_VERSION() so other modules can depend on geom_flashmap(4).
- Remove redundant/superfluous GEOM routines that either do nothing
or provide/just call default GEOM (slice) functionality.
- Trim/adjust includes

Submitted by: jhibbits (RouterBoard bits)
Reviewed by: jhibbits

bhnd(4): Perform explicit chipc child enumeration.

Replaces use of DEVICE_IDENTIFY with explicit enumeration of chipc
child devices using the chipc capability structure.

This is a precursor to PMU support, which requires more complex resource
assignment handling than achievable with the static device name-based
hints table.

Reviewed by: Michael Zhilin <mizkha@gmail.com> (Broadcom MIPS support)
Approved by: re (gjb), adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D6896

bhnd(4): Add support for chipc-attached flash

This adds support for serial (via SPI) and parallel (via CFI) flash
as found on BCM47xx/BCM53xx SoCs.

Submitted by: Michael Zhilin <mizhka@gmail.com>
Approved by: adrian (mentor)
Differential Revision: https://reviews.freebsd.org/D6250