This patch adds a new callback named need_reprint for menu. The need_reprint will be called before printing the menu. If the callback exists and returns FALSE, menu printing will be canceled. This is very useful if the menu was not changed. It can save time for serial-based menu to handle more input data. Signed-off-by: Weijie Gao <weijie.gao@mediatek.com> Reviewed-by: Daniel Golle <daniel@makrotopia.org> Tested-by: Daniel Golle <daniel@makrotopia.org>