drm: omapdrm: dss: Store the debugfs root directory in struct dss_device

As part of an effort to remove the usage of global variables in the
driver, store the debugfs root directory in the dss_device structure
instead of a global variable.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

drivers/gpu/drm/omapdrm/dss/venc.c

@@ -917,7 +917,8 @@ static int venc_bind(struct device *dev, struct device *master, void *data)
 		goto err_probe_of;
 	}
 
-	venc.debugfs = dss_debugfs_create_file("venc", venc_dump_regs, &venc);
+	venc.debugfs = dss_debugfs_create_file(dss, "venc", venc_dump_regs,
+						&venc);
 
 	venc_init_output(pdev);