update bootloader build shell script for generate patch

guowenxue

2022-06-30 b0b21f04ce875cb3df23882018f9a6e6a4cb0dca

 bsp/bootloader/build.sh

@@ -89,8 +89,10 @@
    pr_warn "Clean ${UBOOT_SRC} source code"

    cd ${UBOOT_SRC}
    make savedefconfig
    mv defconfig configs/$defconf
    if [ -f .config ] ; then
        make savedefconfig
        mv defconfig configs/$defconf
    fi
    make distclean
    cd -