drm/xlnx: Run DRM default client setup

Call drm_client_setup_with_fourcc() 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
v2:
- use drm_client_setup_with_fourcc()

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: Michal Simek <michal.simek@amd.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-48-tzimmermann@suse.de

drivers/gpu/drm/xlnx/Kconfig

@@ -6,6 +6,7 @@ config DRM_ZYNQMP_DPSUB
 	depends on PHY_XILINX_ZYNQMP
 	depends on XILINX_ZYNQMP_DPDMA
 	select DMA_ENGINE
+	select DRM_CLIENT_SELECTION
 	select DRM_DISPLAY_DP_HELPER
 	select DRM_DISPLAY_HELPER
 	select DRM_BRIDGE_CONNECTOR

drivers/gpu/drm/xlnx/zynqmp_kms.c

@@ -14,6 +14,7 @@
 #include <drm/drm_blend.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_bridge_connector.h>
+#include <drm/drm_client_setup.h>
 #include <drm/drm_connector.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_device.h>
@@ -402,6 +403,7 @@ static const struct drm_driver zynqmp_dpsub_drm_driver = {
 					  DRIVER_ATOMIC,
 
 	DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE(zynqmp_dpsub_dumb_create),
+	DRM_FBDEV_DMA_DRIVER_OPS,
 
 	.fops				= &zynqmp_dpsub_drm_fops,
 
@@ -523,7 +525,7 @@ int zynqmp_dpsub_drm_init(struct zynqmp_dpsub *dpsub)
 		goto err_poll_fini;
 
 	/* Initialize fbdev generic emulation. */
-	drm_fbdev_dma_setup(drm, 24);
+	drm_client_setup_with_fourcc(drm, DRM_FORMAT_RGB888);
 
 	return 0;