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

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

dwc: Remove if_dwc_mac_type

This doesn't represent the mac_type but if the DMA engine support
extended descriptors.
Read the HW_FEATURE register to learn if the DMA engine supports it.

No functional changes intended.

dwc: Rename if_dwc.h to dwc1000_reg.h

Synopsis/Designware controller have multiple version. The version currently
supported by dwc(4) is the version 3 and it's usually called 1000 for gigabit.
This file only have definition for the registers of this version so rename it.

No functional changes intended.

dwc: Rewrite clock and reset functions

snps,dwmac have one required clock named stmmaceth and one optional pclk,
correctly handle both in if_dwc, no need to get/enable stmmacseth again
in if_dwc_rk.
It also have one required reset also named stmmaceth and one optional ahb,
correctly handle both.
Rockchip have another optional clock named clk_mac_speed, get it and enable it
if present. Also fix the optional RMII clocks, they were previously wrongly
enabled in RGMII case.

dwc: Move every sub drivers to dev/dwc

It makes it easier to find all the sub drivers and change them if needed.
While here do not gate dwc_rk with soc options, dwc_rk is made for all rockchip
SoCs. Same thing for dwc_socfpga