MFC r249257:

MFC r249257:
  Add support for getting and setting BBU properties related to battery
  relearning. Specifically, add subcommands to mfiutil(8) which allow the
  user to set the BBU and autolearn modes when the firmware supports it,
  and add a subcommand which kicks off a battery relearn.

MFC r249258:
  Switch to a 2-clause license.

git-svn-id: svn://svn.freebsd.org/base/stable/9@250482 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f