drm/xe/display: Add struct i915_active for Xe

Add empty definition for struct i915_active 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_types.h

+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef _I915_ACTIVE_TYPES_H_
+#define _I915_ACTIVE_TYPES_H_
+
+struct i915_active {};
+#define I915_ACTIVE_RETIRE_SLEEPS 0
+
+#endif /* _I915_ACTIVE_TYPES_H_ */