drm/i915: Make IS_IVYBRIDGE only take dev_priv

Saves 848 bytes of .rodata strings.

v2: Add parantheses around dev_priv. (Ville Syrjala)
v3: Rebase.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: David Weinehall <david.weinehall@linux.intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 73a521f..d0f798c 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -1084,7 +1084,7 @@
 
 	case 7:
 	case 8:
-		if (IS_IVYBRIDGE(dev)) {
+		if (IS_IVYBRIDGE(to_i915(dev))) {
 			intel_plane->can_scale = true;
 			intel_plane->max_downscale = 2;
 		} else {