drm/vc4: 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 <[e-mail]>
Cc: Maxime Ripard <[e-mail]>
Cc: Dave Stevenson <[e-mail]>
Cc: Raspberry Pi Kernel Maintenance <[e-mail]>
Reviewed-by: Dave Stevenson <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/vc4/Kconfig

···
 	depends on SND && SND_SOC
 	depends on COMMON_CLK
 	depends on PM
+	select DRM_CLIENT_SELECTION
 	select DRM_DISPLAY_HDMI_HELPER
 	select DRM_DISPLAY_HDMI_STATE_HELPER
 	select DRM_DISPLAY_HELPER

drivers/gpu/drm/vc4/vc4_drv.c

···
 
 #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_dma.h>
+#include <drm/drm_fourcc.h>
 #include <drm/drm_vblank.h>
 
 #include <soc/bcm2835/raspberrypi-firmware.h>
···
 	.gem_create_object = vc4_create_object,
 
 	DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE(vc4_bo_dumb_create),
+	DRM_FBDEV_DMA_DRIVER_OPS,
 
 	.ioctls = vc4_drm_ioctls,
 	.num_ioctls = ARRAY_SIZE(vc4_drm_ioctls),
···
 	if (ret < 0)
 		goto err;
 
-	drm_fbdev_dma_setup(drm, 16);
+	drm_client_setup_with_fourcc(drm, DRM_FORMAT_RGB565);
 
 	return 0;