drm/rockchip: Run DRM default client setup

drm/rockchip: 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.

v5:
- select DRM_CLIENT_SELECTION

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sandy Huang <hjc@rock-chips.com>
Cc: "Heiko Stübner" <heiko@sntech.de>
Cc: Andy Yan <andy.yan@rock-chips.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-38-tzimmermann@suse.de