broadcom/vc4: Don't advertise tiled dmabuf modifiers if we can't use them

broadcom/vc4: Don't advertise tiled dmabuf modifiers if we can't use them

If the DRM_VC4_GET_TILING ioctl isn't present then we can't tell
if a dmabuf bo is tiled or linear, so will always assume it's
linear.

By not advertising tiled formats in this situation we ensure the
assumption is correct.

This fixes a bug where most attempts to render a gl wayland client
under weston will result in a client side abort.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Stone <daniels@collabora.com> (on irc)