sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

arm/arm64 freescale: Remove unused devclass arguments to DRIVER_MODULE.

arm: clean up empty lines in .c and .h files

Move imx6_usbphy to SUPPORTDEV, massage associated comment

No objections from: ian

sys/arm: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Support the "disable-over-current" property for imx ehci controllers.

It turns out that this is more than a power optization. The OTG port
won't work on boards that have this property unless this setting is honored.

Also ensure that the usb phy device attaches before ehci.

Convert probing to use an ofw_compat_data array, and add imx6ul to the list.

Enable usb low and full speed devices connected to the imx6 root hubs.

This enables the PHY circuitry for UTMI+ level 2 and 3, and sets the
flag to tell the ehci code that the root hub has a transaction translator
in it. For imx6 we can use the standard ehci_get_port_speed_portsc()
function to find out what speed device is connected to the port.

Stop calling imx51_ccm_foo() clock functions from imx6 code. Instead
define a few imx_ccm_foo() functions that are implemented by the imx51 or
imx6 ccm code. Of course, the imx6 ccm code is still more a wish than
reality, so for now its implementations just return hard-coded numbers.

Follow r261352 by updating all drivers which are children of simplebus
to check the status property in their probe routines.

Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352. Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.

Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.

Fix undefined behavior: (1 << 31) is not defined as 1 is an int and this
shifts into the sign bit. Instead use (1U << 31) which gets the
expected result.

This fix is not ideal as it assumes a 32 bit int, but does fix the issue
for most cases.

A similar change was made in OpenBSD.

Discussed with: -arch, rdivacky
Reviewed by: cperciva

Add support for the USB PHY on imx6 SoCs. Pretty minimal at this point,
but enough to get usb host mode working.