sbin: 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

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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

nvme: fix resv commands with nda device

- passing I/O commands through nda requires nsid field to be set (it was
unused when going through nvme_ns_ioctl())
- ccb's status can be OR'ed with the flags, use CAM_STATUS_MASK

Reviewed by: imp (cam)
Differential Revision: https://reviews.freebsd.org/D37696

Improve nvmecontrol error reporting.

MFC after: 1 week
Sponsored by: iXsystems, Inc.

Open device with O_RDONLY when command is non-invasive.

This allows to use some of the subcommands against mounted nvd devices.

MFC after: 1 week
Sponsored by: iXystems, Inc.

Fix alignment issue r350599.

MFC after: 10 days

Add `nvmecontrol resv` to handle NVMe reservations.

NVMe reservations are quite alike to SCSI persistent reservations and
can be used in clustered setups with shared multiport storage.

MFC after: 10 days
Relnotes: yes
Sponsored by: iXsystems, Inc.