Adds syntax highlighting to coreboot devicetree.cb files in Atom.
These keywords were pulled from the sconfig.l file in coreboot's util/sconfig/sconfig.l file.
http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=util/sconfig/sconfig.l
To add the grammar manually under linux, place the language-devicetree directory or a symbolic link to it into the ~/.atom/packages directory. In windows, it goes into the users//.atom/packages directory.