drm/i915: Initialize skylake scalers

Initializing scalers with supported values during crtc init.

v2:
-initialize single copy of min/max values (Matt)

v3:
-moved gen check to callsite (Matt)

v4:
-squashed planes begin with no scaler to here (me)

v5:
-updated init function with updated scaler state structure (Matt)

Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 7d1a5b8..6d4e1ea 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -1294,6 +1294,7 @@
 		intel_plane->max_downscale = 1;
 		intel_plane->update_plane = skl_update_plane;
 		intel_plane->disable_plane = skl_disable_plane;
+		state->scaler_id = -1;
 
 		plane_formats = skl_plane_formats;
 		num_plane_formats = ARRAY_SIZE(skl_plane_formats);