Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r244787, 244796:

Add DEVICE_IDENTIFY method for wbwd(4), required on most of recent
Supermicro motherboards.

Tested on X8STi and X8DTH boards.

Sponsored by: iXsystems, Inc.

MFC r233648:
Remove trailing whitespace per mdoc lint warning

Approved by: cperciva (implicit)

MFC r232614:

Provide wbwd(4), a driver for the watchdog timer found on various
Winbond Super I/O chips.

Provide wbwd(4), a driver for the watchdog timer found on various
Winbond Super I/O chips.

With minor efforts it should be possible the extend the driver to support
further chips/revisions available from Winbond. In the simplest case
only new IDs need to be added, while different chipsets might require
their own function to enter extended function mode, etc.

Sponsored by: Sandvine Incorporated ULC (in 2011)
Reviewed by: emaste, brueffer
MFC after: 2 weeks