MFC r343572:
Add support for Audio Sink and Audio Source profiles to sdpd(8).

This allows user-space programs like virtual_oss(8) to act
as a Bluetooth speaker device.

Sponsored by: Mellanox Technologies

MFC r326276:

various: general 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.

No functional change intended.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Check l2cap socket initialisation and define L2CAP_SOCKET_CHECKED
This will fix build.

Add PSM and Load Factor SDP parameters to the BNEP based profiles
(NAP, GN and PANU). No reason to not to support them.

Separate SDP parameters data structures for the BNEP based profiles.

Generalize Service Availability SDP parameter creation.

Requested by: Iain Hibbert < plunky at rya-online dot net >
MFC after: 3 days

Add support for the NAP, GN and PANU profiles to the sdpd(8).
It should be mentioned that a somewhat similar patch was
submitted by Rako < rako29 at gmail dot com >

MFC after: 1 week

Avoid casts as lvalues.

Import sdpd(8) sources. This is Bluetooth Service Discovery Protocol daemon.
Extend libsdp(3) API to allow service registration and removal.
Fix uninitialized variable bug in sdpcontrol(8).

Reviewed by: imp (mentor)
No objection: ru