drm/{i915,xe}: Unregister in-kernel clients

Unregister all in-kernel clients before unloading the i915 driver. For
other drivers, drm_dev_unregister() does this automatically. As i915 and
xe do not use this helper, they have to perform the call by themselves.

Note that there are currently no in-kernel clients in i915 or xe. The
patch prepares the drivers for a related update of their fbdev support.

v8:
- unregister clients in intel_display_driver_unregister() (Jani)
- mention xe in commit message (Rodrigo, Jani)

v7:
- update xe driver

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240409081029.17843-5-tzimmermann@suse.de
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

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

@@ -11,6 +11,7 @@
 #include <acpi/video.h>
 #include <drm/display/drm_dp_mst_helper.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_client.h>
 #include <drm/drm_mode_config.h>
 #include <drm/drm_privacy_screen_consumer.h>
 #include <drm/drm_probe_helper.h>
@@ -640,6 +641,8 @@ void intel_display_driver_unregister(struct drm_i915_private *i915)
 	if (!HAS_DISPLAY(i915))
 		return;
 
+	drm_client_dev_unregister(&i915->drm);
+
 	intel_fbdev_unregister(i915);
 	/*
 	 * After flushing the fbdev (incl. a late async config which

drivers/gpu/drm/xe/xe_device.c

@@ -9,6 +9,7 @@
 
 #include <drm/drm_aperture.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_client.h>
 #include <drm/drm_gem_ttm_helper.h>
 #include <drm/drm_ioctl.h>
 #include <drm/drm_managed.h>