Assert an MIT copyright on sis_drm.h, since one was lacking and I created

    that particular file. Its contents have changed a good bit since the
    original sis code, and the original sis code didn't care much about
    attribution since it routinely disclaims Precision Insight/VA Linux
    from responsibility. Also, adjust formatting around license headers
    (have a comment open immediately before the "Copyright" line, not as a
    runon of any previous comments) for automatic processing into FreeBSD,
    where /*- is used to signal the beginning of license headers for
    automatic compilation of license lists.