Revert r276101, it didn't fix the problem and causes a compile error
(nested comment blocks).


git-svn-id: svn+ssh://svn.freebsd.org/base/head@276161 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Don't assume required FDT properties are present.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@276162 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f