drm/virtgpu: Run DRM default client setup

Call drm_client_setup() to run the kernel's default client setup
for DRM. Set fbdev_probe in struct drm_driver, so that the client
setup can start the common fbdev client.

The virtgpu driver specifies a preferred color mode of 32. As this
is the default if no format has been given, leave it out entirely.

v5:
- select DRM_CLIENT_SELECTION

Signed-off-by: Thomas Zimmermann <[e-mail]>
Cc: David Airlie <[e-mail]>
Cc: Gerd Hoffmann <[e-mail]>
Cc: Gurchetan Singh <[e-mail]>
Cc: Chia-I Wu <[e-mail]>
Acked-by: Javier Martinez Canillas <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/virtio/Kconfig

···
 	tristate "Virtio GPU driver"
 	depends on DRM && VIRTIO_MENU && MMU
 	select VIRTIO
+	select DRM_CLIENT_SELECTION
 	select DRM_KMS_HELPER
 	select DRM_GEM_SHMEM_HELPER
 	select VIRTIO_DMA_SHARED_BUFFER

drivers/gpu/drm/virtio/virtgpu_drv.c

···
 #include <drm/drm.h>
 #include <drm/drm_aperture.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_client_setup.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_fbdev_shmem.h>
 #include <drm/drm_file.h>
···
 	if (ret)
 		goto err_deinit;
 
-	drm_fbdev_shmem_setup(vdev->priv, 32);
+	drm_client_setup(vdev->priv, NULL);
+
 	return 0;
 
 err_deinit:
···
 
 	.dumb_create = virtio_gpu_mode_dumb_create,
 	.dumb_map_offset = virtio_gpu_mode_dumb_mmap,
+
+	DRM_FBDEV_SHMEM_DRIVER_OPS,
 
 #if defined(CONFIG_DEBUG_FS)
 	.debugfs_init = virtio_gpu_debugfs_init,