driver, gpiolock(4), is provided as an example how to interface real hardware.
A new securemodel, securemodel_keylock, is provided to show how this can
be used to tie keylocks to overall system security. This is experimental
code. The diff has been on tech-kern for several weeks.
Reviewed by many, kauth(9) integration reviewed by Elad Efrat; approved by
tonnerre@ and tron@. Thanks to everyone who provided feedback.
