sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

Remove NAND and NANDFS support

NANDFS has been broken for years. Remove it. The NAND drivers that
remain are for ancient parts that are no longer relevant. They are
polled, have terrible performance and just for ancient arm
hardware. NAND parts have evolved significantly from this early work
and little to none of it would be relevant should someone need to
update to support raw nand. This code has been off by default for
years and has violated the vnode protocol leading to panics since it
was committed.

Numerous posts to arch@ and other locations have found no actual users
for this software.

Relnotes: Yes
No Objection From: arch@
Differential Revision: https://reviews.freebsd.org/D20745

Support device-independent labels for geom_flashmap slices.

While geom_flashmap has always supported label names for its slices, it does
so by appending "s.labelname" to the provider device name, meaning you still
have to know the name and unit of the hardware device to use the labels.

These changes add support for device-independent geom_flashmap labels, using
the standard geom_label infrastructure. geom_flashmap now creates a softc
struct attached to its geom, and as it creates slices it stores the label
into an array in the softc. The new geom_label_flashmap uses those labels
when tasting a geom_flashmap provider.

Differential Revision: https://reviews.freebsd.org/D19535

sys/geom: adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

- 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

Teach the flashmap code about the SPI flash.

PR: kern/206227
Submitted by: Stanislav Galabov <sgalabov@gmail.com>

Create a RouterBoard platform and use it to create a flash map

Summary:
The RouterBoard uses a predefined partition map which doesn't exist in the fdt.
This change allows overriding the fdt slicer with a custom slicer, and uses this
custom slicer to define the flash map on the RouterBoard RB800.
D3305 converts the mpc85xx platform into a base class, so that systems based on
the mpc85xx platform can add their own overrides. This change builds on D3305,
and creates a RouterBoard (RB800) platform to initialize the slicer override.

Reviewed By: nwhitehorn, imp
Differential Revision: https://reviews.freebsd.org/D3345

MFP4 @222836

Add support for partitioning CFI disks from FDT using geom_flashmap.

Sponsored by: DARPA, AFRL

Partial MFP4 of 222836:

Only look for FDT partitions if our potential parent is a DISK device.

Excluding direct recursion on the flashmap geoms was insufficient
because it did not prevent the underlying device from being retrieved if
flashmap geoms were further partitioned.

Reviewed by: imp
Sponsored by: DARPA, AFRL

- Correct signedness for casts;
- Wrap long line while I'm there.

Noticed by: pjd, avg

Use %ju to match uintmax_t usage

Use %j and cast off_t to intmax_t for now to fix build.

Noticed by: bz

Add a new geom class which allows to divide NAND Flash chip
into partitions.

Partitions are created based on data in dts file which are
extracted and interpreted by slicer.

Obtained from: Semihalf
Supported by: FreeBSD Foundation, Juniper Networks