Since kernel 6.3, bq25890 driver allows to enable Hi-Z via sysfs.

This reverts commit f5a7a6a4.

We want ship mode enabled.

If the device is in ship mode then it powers on when the charging cable is plugged in. To be in compliance with the power saving regulations below we can't turn on when power is applied.

  10 Code CFR Part 430 (the energy conservation standards specified
  in the Code of Federal Reguklations at 10 CFR 430.32(z))

  California Code Of Regulations, Title 20: Division 2, Chapter 4,
  Article Appendix 4, Sections 1601‐1609: Appliance Efficiency Regulations

This reverts commit 86c1e578.

When powering off (not rebooting) the Librem 5 battery should be put
into shipmode in order to preserve its' capacity. For the whole
discussion, see https://source.puri.sm/Librem5/linux-next/-/issues/120

When USB power is plugged in during powering off, we don't change
any behaviour though. Setting shipmode in that situation would
make charging stop when powering off. Of course this means that
if the phone is shut down while plugged in and unplugged later,
the battery will still discharge slowly.

Only when unplugged, running on battery only, during shutdown,
we set shipmode and prevent the battery to discharge while the
phone is powered off.