bios: Delete uploaded DBus object after update

When the BIOS code update is completed, delete the uploaded DBus object
so that only the "bios_active" object remains.
Otherwise it leaves the uploaded DBus object that does not reflect a
real thing.

Tested: Verify only bios_active remains and the uploaded BIOS object is
        deleted from DBus, and it is possible to upload and update the
        same BIOS tarball for multieple times.

Signed-off-by: Lei YU <yulei.sh@bytedance.com>
Change-Id: I18e76238821f48a3b322594bb359fcb37f28f397
3 files changed