drm/logicvc: 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 logicvc driver specifies a preferred color mode from the value
in struct drm_mode_config.preferred_depth. The fbdev client also
looks at this value for the default pixel format. Thus remove the
format selection from logicvc.

v5:
- select DRM_CLIENT_SELECTION

Signed-off-by: Thomas Zimmermann <[e-mail]>
Cc: Paul Kocialkowski <[e-mail]>
Acked-by: Javier Martinez Canillas <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/logicvc/Kconfig

···
 	tristate "LogiCVC DRM"
 	depends on DRM
 	depends on OF || COMPILE_TEST
+	select DRM_CLIENT_SELECTION
 	select DRM_KMS_HELPER
 	select DRM_KMS_DMA_HELPER
 	select DRM_GEM_DMA_HELPER

drivers/gpu/drm/logicvc/logicvc_drm.c

···
 #include <linux/types.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_gem_dma_helper.h>
 #include <drm/drm_print.h>
 
···
 	.minor				= 0,
 
 	DRM_GEM_DMA_DRIVER_OPS_VMAP_WITH_DUMB_CREATE(logicvc_drm_gem_dma_dumb_create),
+	DRM_FBDEV_DMA_DRIVER_OPS,
 };
 
 static struct regmap_config logicvc_drm_regmap_config = {
···
 	struct regmap *regmap = NULL;
 	struct resource res;
 	void __iomem *base;
-	unsigned int preferred_bpp;
 	int irq;
 	int ret;
 
···
 		goto error_mode;
 	}
 
-	switch (drm_dev->mode_config.preferred_depth) {
-	case 16:
-		preferred_bpp = 16;
-		break;
-	case 24:
-	case 32:
-	default:
-		preferred_bpp = 32;
-		break;
-	}
-	drm_fbdev_dma_setup(drm_dev, preferred_bpp);
+	drm_client_setup(drm_dev, NULL);
 
 	return 0;