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

Add support for the Sharp/Micron flash chips to powermac_mvram(4).
Tested on PowerMac G4 AGP.

Reviewed by: nwhitehorn

Add device to access and modify Open Firmware NVRAM settings in
PowerPC-based Apple's machines and small utility to do it from
userland modelled after the similar utility in Darwin/OSX.

Only tested on 1.25GHz G4 Mac Mini.

MFC after: 1 month