buildman: Show progress when regenerating the board.cfg file

This can take a while, so show a message when starting.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by Tom Rini <trini@konsulko.com>
diff --git a/tools/buildman/control.py b/tools/buildman/control.py
index f2ffb7f..8f6850c 100644
--- a/tools/buildman/control.py
+++ b/tools/buildman/control.py
@@ -621,7 +621,8 @@
     if not brds:
         brds = get_boards_obj(output_dir, args.regen_board_list,
                               args.maintainer_check, args.full_check,
-                              args.threads, args.verbose)
+                              args.threads, args.verbose and
+                              not args.print_arch and not args.print_prefix)
         if isinstance(brds, int):
             return brds