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

phy: Move phy code in dev/phy

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/D43195

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

hwreset: Move reset code in dev/hwreset

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: imp
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D43192

clk: Move clock code in dev/clk

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/D43191

Fix style.

Improve RK3568 pcie phy handling codes a bit.

Move phy bifurcation code to a separate function
that can be called during the attach phase.
Also initialize both pcie lanes accordingly.

Fix pcie phy enabling codes for RK3568 SoC.

Handle data-lanes property for pcie phy and set it accordingly.
This makes devices attached to pcie3 work properly.
For some RK3568 based boards, RTL8125B based device is
connected it. So with this, realtek-re-kmod driver attaches
and works.

Partially obtained from OpenBSD.
Tested on NanoPI-R5S, FireFly Station P2 boards.

Remove unnecessary sys/cdefs.h includes.

Use BSD-2-Clause for the SPDX license id as -FreeBSD variant has been deprecated.

Remove unnecessary $Id string from license.

While there add SPDX-License-Identifier.

Add PCIe driver for RK3568 SoC.

PCIe3 ports work, however PCIe2x1 is not working yet in this case as it depends on Naneng Combo Phy driver.