x86/ucode: add support for early loading of CPU ucode on AMD.

Sponsored by: Netflix
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D43318

usr.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/

cpucontrol(8): Fix a typo in an error message

- s/incorret/incorrect/

MFC after: 1 week

cpucontrol(8): De-duplicate common update logic

Every µcode-updater must open the cpucontrol devfs node RDWR, open a
firmware file, validate the FW file has a positive length, mmap it, etc.
De-duplicate that identical logic between every individual platform.

Also, constify references to the readonly-mapped firmware files while here.

Sponsored by: Dell EMC Isilon

cpucontrol: correct typo

There should be no 't' in processort_rev_id.

Approved by: re (gjb)
Sponsored by: The FreeBSD Foundation

Use the existing MSR_BIOS_SIGN on AMD.

Reported by: kib
Sponsored by: The FreeBSD Foundation

Use the name added in r336257.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

cpucontrol:
- fix debugging for family on AMD cpus and add useful debugging for
which file is being selected for update.

Reviewed by: cem
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15574

Add support for microcode update on newer AMD CPUs (10h+)

This includes new code for parsing microcode files as well as
the kernel-side change to apply the update on all processors
at the same time.

Developed with help from Borislav Petkov, formerly bp@amd64.org.

Tested using Athlon II X2 processor on a system where BIOS does
not have the latest microcode version:
/boot/firmware/microcode_amd.bin: updating cpu /dev/cpuctl0 to revision 0x10000c7... done.

The microcode file is taken from here:
https://web.archive.org/web/20160528230514/http://www.amd64.org/microcode.html
(note that the original site seems to be down at the moment)
It can also be found here:
https://git.kernel.org/cgit/linux/kernel/git/firmware/linux-firmware.git/tree/amd-ucode

Reviewed by: kib, stas
MFC after: 2 weeks
Relnotes: maybe
Differential Revision: https://reviews.freebsd.org/D8384