drm/xe/display: Add empty define for i915_ggtt_clear_scanout

Add empty define for i915_ggtt_clear_scanout to avoid build failure.
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/compat-i915-headers/i915_vma.h

@@ -22,6 +22,7 @@ struct i915_vma {
 	struct drm_mm_node node;
 };
 
+#define i915_ggtt_clear_scanout(bo) do { } while (0)
 
 static inline u32 i915_ggtt_offset(const struct i915_vma *vma)
 {