dm: fix formatting of uclass dump

Insert an empty line after each uclass independent of whether it has
devices or not.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/drivers/core/dump.c b/drivers/core/dump.c
index fe97dca..21d9e7a 100644
--- a/drivers/core/dump.c
+++ b/drivers/core/dump.c
@@ -89,8 +89,6 @@
 			continue;
 
 		printf("uclass %d: %s\n", id, uc->uc_drv->name);
-		if (list_empty(&uc->dev_head))
-			continue;
 		uclass_foreach_dev(dev, uc) {
 			dm_display_line(dev, i);
 			i++;