drm/i915/display: clean up some gem/ includes

Drop some unnecessary gem/ includes.

We seem to include xe_device.h through some compat gem headers, so we
need to include it directly in compat i915_drv.h to get
xe_device_has_flat_ccs().

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/afd2917cc0a943660886937bb5f45c277132e147.1726589119.git.jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_cursor.c

@@ -27,8 +27,6 @@
 #include "intel_vblank.h"
 #include "skl_watermark.h"
 
-#include "gem/i915_gem_object.h"
-
 /* Cursor formats */
 static const u32 intel_cursor_formats[] = {
 	DRM_FORMAT_ARGB8888,

drivers/gpu/drm/i915/display/intel_fb.c

@@ -3,14 +3,13 @@
  * Copyright © 2021 Intel Corporation
  */
 
-#include <drm/drm_blend.h>
-#include <drm/drm_modeset_helper.h>
-
 #include <linux/dma-fence.h>
 #include <linux/dma-resv.h>
 
-#include "gem/i915_gem_object.h"
-#include "gem/i915_gem_object_types.h"
+#include <drm/drm_blend.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_modeset_helper.h>
+
 #include "i915_drv.h"
 #include "intel_atomic_plane.h"
 #include "intel_bo.h"

drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h

@@ -14,6 +14,7 @@
 
 #include "i915_utils.h"
 #include "intel_runtime_pm.h"
+#include "xe_device.h" /* for xe_device_has_flat_ccs() */
 #include "xe_device_types.h"
 
 static inline struct drm_i915_private *to_i915(const struct drm_device *dev)