boot: Drop size parameter from image_setup_libfdt()

The of_size parameter is not used, so remove it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/boot/image-board.c b/boot/image-board.c
index bb0ca9d..75f6906 100644
--- a/boot/image-board.c
+++ b/boot/image-board.c
@@ -908,7 +908,7 @@
 	}
 
 	if (CONFIG_IS_ENABLED(OF_LIBFDT) && of_size) {
-		ret = image_setup_libfdt(images, *of_flat_tree, of_size, lmb);
+		ret = image_setup_libfdt(images, *of_flat_tree, lmb);
 		if (ret)
 			return ret;
 	}