drm: make DRI1 drivers depend on BROKEN

The legacy DRI1 drivers expose highly broken interfaces to user-space. No
modern system should enable them, or you will effectively allow user-space
to circumvent most of your kernel security measures. The DRI1 kernel APIs
are simply broken.

User-space can always use vesafb/efifb/simplefb and friends to get working
graphics.

Lets hide the old drivers behind CONFIG_BROKEN. In case they turn out to
be still used (really?), we can easily revert this and figure out a way to
move them out of sight (e.g., moving all DRI1 drivers to
drivers/gpu/dri1/).

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20160804080657.9664-2-dh.herrmann@gmail.com