syscon: Move syscon code in dev/syscon

We've removed kernel option EXT_RESOURCES almost two years ago.
While it was ok to have some code under a common 'extres' subdirectory
at first, we now have a lot of consumer of it and we made it mandatory
so no need to have it under a cryptic name.

Reviewed by: mhorne
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D43196

regulator: Move regulator code in dev/regulator

We've removed kernel option EXT_RESOURCES almost two years ago.
While it was ok to have some code under a common 'extres' subdirectory
at first, we now have a lot of consumer of it and we made it mandatory
so no need to have it under a cryptic name.

Reviewed by: emaste, imp
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D43194

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/

arm64: rockchip: Tweak i2c, pmic and iodomain order

We need i2c first to set it to MIDDLE, then we need one of the pmics
so set them to LATE, only then we can attach iodomain which needs some
regulators exposed by the pmic so set it to LAST.

Sponsored by: Beckhoff Automation GmbH & Co. KG

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

Add RockChip RK356X support to existing RockChip iodomain driver.

arm64 rockchip: Remove unused devclass arguments to DRIVER_MODULE.

Multiple fixes for rockchip iodomain driver:
- always initialize selector of voltage signaling standard.
Various versions of U-boot leaves voltage signaling standard settings
for PMUIO2 domain in different state. Always initialize it
into expected state.
- start the driver as early as possible, the IO domains should be
initialized before other drivers are attached.
- rename RK3399 register to its name founds in TRM.

This is the second part of fixes for serial port corruption observed after
DT 5.6 import.

Reviewed by: manu
MFC after: 1 week

arm64: rockchip: Add driver for the io domain

This driver configure the registers in the GRF according to the value
of the regulators for the platform.
Some IP can run with either 3.0V or 1.8V, if we don't configure them
correctly according to the external voltage used they will not work.
It's only done at boot time for now and might be needed at runtime for
IP like sdmmc.

Reviewed by: mmel
Tested On: RockPro64, Firefly-RK3399 (gonzo), AIO-3288 (mmel)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D22854