Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

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

Use standard types in preference to BSD types so that these header files
can be used in applications compiled with only POSIX types visible.

MFC after: 2 weeks

Start each of the license/copyright comments with /*-, minor shuffle of lines

Make the multiple include guard correct for this file location.
This fixes a bug where the guard conflicted with machine/ioctl_*.

Repo copied from sys/i386/include. All the <arch>/machine ones are
going to share this copy.

Ooops. These are still used by the bktr driver. David O'Brien has
plans for dealing, but I'll let him deal.

Pointy hat to: imp@