Revert "Support flash from local files for auto_flash_from_pvt.sh."

This reverts commit c28ebb5c246ff53295fb9153e6779398f1c910b1.
Merge pull request #95 from askeing/revert_support_flash_from_local_files

Revert "Support flash from local files for auto_flash_from_pvt.sh."
Support flash from local files for auto_flash_from_pvt.sh.
[Ubuntu]