drm/arm/hdlcd: 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 hdlcd 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 <tzimmermann@suse.de>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240924071734.98201-9-tzimmermann@suse.de

drivers/gpu/drm/arm/Kconfig

@@ -6,6 +6,7 @@ config DRM_HDLCD
 	tristate "ARM HDLCD"
 	depends on DRM && OF && (ARM || ARM64 || COMPILE_TEST)
 	depends on COMMON_CLK
+	select DRM_CLIENT_SELECTION
 	select DRM_KMS_HELPER
 	select DRM_GEM_DMA_HELPER
 	help

drivers/gpu/drm/arm/hdlcd_drv.c

@@ -23,6 +23,7 @@
 
 #include <drm/drm_aperture.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_client_setup.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_debugfs.h>
 #include <drm/drm_drv.h>
@@ -228,6 +229,7 @@ DEFINE_DRM_GEM_DMA_FOPS(fops);
 static const struct drm_driver hdlcd_driver = {
 	.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
 	DRM_GEM_DMA_DRIVER_OPS,
+	DRM_FBDEV_DMA_DRIVER_OPS,
 	.fops = &fops,
 	.name = "hdlcd",
 	.desc = "ARM HDLCD Controller DRM",
@@ -299,7 +301,7 @@ static int hdlcd_drm_bind(struct device *dev)
 	if (ret)
 		goto err_register;
 
-	drm_fbdev_dma_setup(drm, 32);
+	drm_client_setup(drm, NULL);
 
 	return 0;