MFC r340845-r340848, r340971, r340981, r342076

r340845:
Derive PHY class to new one specialized for USB PHY functions.

Submitted by: mmel

r340846:
aw_usbphy: Convert to usbphy subclass

Instead of routing the phy when enabling it, do the configuration
and routing in the phynode_usb_set_mode function.
While here, if we don't have a vbus detection method, enable the phy
if requested.

r340847:
a10_ehci: Always set the phy to host mode

r340848:
axp8xx: Rework the enable part and add the GPIOXLDO regulators

r340971:
aw_usbphy: Do not error if it's not phy 0

Only phy0 can switch between host/otg, do not error if we request
host mode on phy != 0.

X-MFC with: r340846

r340981:
release: arm64: Add PINEBOOK config

Add a configuration for PINEBOOK image.
Pinebook is a arm64 laptop based on a Pine64 board.

Since the usb trackpad need a quirk, add a common function for adding
quirk for arm board.
A default one is supplied as most board to not need quirks.

Reviewed by: gjb
Differential Revision: https://reviews.freebsd.org/D18337

r342076:
arm64: allwinner: axp81x: Fix double invertion for FLDO1

This fix booting on A64 boards when disabling the unused regulators at boot.
We did disable all the regulator handled by register 0x13 which of course contain
mandatory regulators for the board to be up.

Reported by: Mark Millard <marklmi@yahoo.com>
X-MFC-With: r340848