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

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

Use __packed;

A driver for the System Management Application Program
Interface (SMAPI) BIOS, which is present on some IBM
Thinkpad models (560, 600, 770 to name a few.)

The SMAPI BIOS provides access to System Information,
System Configuration, and Power Management.