drm/xe/display: Add i915_active.h compatibility header

Add empty definitions for i915_active_init/fini to kill ifdefs from
frontbuffer tracking code.
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_active.h

+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef _I915_ACTIVE_H_
+#define _I915_ACTIVE_H_
+
+#include "i915_active_types.h"
+
+static inline void i915_active_init(struct i915_active *ref,
+				    int (*active)(struct i915_active *ref),
+				    void (*retire)(struct i915_active *ref),
+				    unsigned long flags)
+{
+	(void) active;
+	(void) retire;
+}
+
+#define i915_active_fini(active) do { } while (0)
+
+#endif