update build_QT5.sh shell script, add comment for unrecognized command line...

guowenxue

2020-07-02 e8f71869179f5c099228958a3d869b20005f7273

linux-bsp/tarballs/linux-3.2.0.tar.xz does not exist in tree 04af810a4441641a70419cf2fe97c8571fcf27fb