drm/i915: Make setting color key atomic.

By making color key atomic there are no more transitional helpers.
The plane check function will reject the color key when a scaler is
active.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Tested-by(IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
4 files changed