tree d2434e57c7e662da28781b2ca08e23dd4846ac8b
parent 9930137b234144a244e953cb1c2aae7d51bd67a3
author Lei YU <mine260309@gmail.com> 1569487343 +0800
committer Lei YU <mine260309@gmail.com> 1571813622 +0000

Activation: store PSU image in persistent storage

When an activation succeeds, store the PSU image into persistent
storage, which will be used in future in case a PSU is replaced, and the
BMC will need to update the replaced PSU's firmware.
Only the latest image is saved, and old ones are removed for each model.

Tested: On witherspoon, verify the PSU image is saved in persistent
        storage after a successful activation with dummy service, and
        the FilePath inteface is updated with the stored path.
        And after another successful activation, the new image is saved
        and the old one is removed in persistent storage.

Signed-off-by: Lei YU <mine260309@gmail.com>
Change-Id: I11f3d4a91d045d2316242d8eef968f05250d862e