dm: Tidy up 'dm tree' output when there are many devices

At present the 'Index' column assumes there is only one digit. But on some
devices (e.g. snow) there are a lot of regulators and GPIO banks. Adjust
the output to allow for two digits without messing up the display.

Also capatalise the heading to match.

Fixes: 5197dafc42 (dm: core: Widen the dump tree to show more of the
driver's name.)

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Liviu Dudau <liviu.dudau@foss.arm.com>
diff --git a/drivers/core/dump.c b/drivers/core/dump.c
index 04217cb..8fbfd93 100644
--- a/drivers/core/dump.c
+++ b/drivers/core/dump.c
@@ -16,7 +16,7 @@
 	struct udevice *child;
 
 	/* print the first 20 characters to not break the tree-format. */
-	printf(" %-10.10s  %d  [ %c ]   %-20.20s  ", dev->uclass->uc_drv->name,
+	printf(" %-10.10s  %2d  [ %c ]   %-20.20s  ", dev->uclass->uc_drv->name,
 	       dev_get_uclass_index(dev, NULL),
 	       dev->flags & DM_FLAG_ACTIVATED ? '+' : ' ', dev->driver->name);
 
@@ -49,7 +49,7 @@
 
 	root = dm_root();
 	if (root) {
-		printf(" Class    index  Probed  Driver                Name\n");
+		printf(" Class     Index  Probed  Driver                Name\n");
 		printf("-----------------------------------------------------------\n");
 		show_devices(root, -1, 0);
 	}