vblank in the kernel is far simpler if it deals with pipes instead of
planes, so we're changing both user and kernel side.
Signed-off-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>