update uboot patch file, add bbl env support

guowenxue

2021-11-14 2808bf2f594f9ffb3017481b3f3b0940bbc29012

 tools/lintools/buildroot/buildroot.sh

@@ -112,7 +112,10 @@
        exit ;
    fi

    echo ""
    echo ""
    echo " Switch work space to \"$WORK_SPACE\" " 
    echo ""
    mkdir -p $WORK_SPACE 
    cd $WORK_SPACE
}