Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

Extend device_get_property API

In order to support various types of data stored in device
tree properties or ACPI _DSD packages, create a new enum so
the caller can specify the expected type of a property they
want to read, according to the binding. The bus logic will use
that information to process the underlying data.

For example in DT all integer properties are stored in BE format.
In order to get constant results across different platforms we
need to convert its endianness to match the host.

Another example are ACPI_TYPE_INTEGER properties stored
as uint64_t. Before this patch the ACPI logic would refuse
to read them if the provided buffer was smaller than 8 bytes.
Now this can be handled by using DEVICE_PROP_UINT32 type.

Modify the existing consumers of this API to reflect the changes
and update the man pages accordingly.

Reviewed by: mw
Obtained from: Semihalf
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D33457

device: add device_get_property and device_has_property

Generialize bus specific property accessors. Those functions allow driver code
to access device specific information.

Currently there is only support for FDT and ACPI buses.

Reviewed by: manu, mw
Sponsored by: Semihalf
Differential revision: https://reviews.freebsd.org/D31597