Make 1-bit fields be unsigned (no sign bit :). sparse complains about them:

    drivers/char/drm/sis_ds.h:88:12: warning: dubious one-bit signed
    bitfield drivers/char/drm/sis_ds.h:89:16: warning: dubious one-bit
    signed bitfield
Signed-off-by: Randy Dunlap <rddunlap@osdl.org> Signed-off-by: Dave Airlie
    <airlied@linux.ie>