drm/i915: Add spurious CRT DMI match for Intel DZ77BH-55K

Intel DZ77BH-55K board doest't have a physical VGA connector,
and yet it always detects that something is connected there.
Add it to the DMI blacklist to ignore the spurious detection
results.

Allows me to drop 'video=VGA-1:d' from my kernel cmdline.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1474881646-1326-3-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>