Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Cleanup some sound headers that don't need to be in the modules makefiles.

Approved by: jhb (mentor)
MFC after: 1 week

Replace GPLd headers from the Maestro3 driver with BSD licensed
versions derived from /usr/ports/audio/oss.

The particular headers used were taken from the
attic/drv/oss_allegro directory and are mostly identical
to the previous files.

The Maestro3 driver is now free from the GPL.

NOTE: due to lack of testers this driver is being
considered for deprecation and removal.

PR: kern/153920
Approved by: jhb (mentor)
MFC after: 2 weeks

isa_if.h is not needed.

No response from: sound

Catch these modules up with obrien's recent cleanup commit.

Driver for the ESS Maestro3 and Allegro sound chips. Note that due to the
amount of GPL'd firmware in the driver, it will only be built as a module.

Approved by: cg