power: power_supply: Add property for ship mode

In ship mode the charger module opens the bat-fet and disconnects the
battery from the system. This is for the non-removable battery designs
to avoid them from being discharged when shipped/on-shelf.

The ship mode is enabled during the final stage of power-off typically
from the PON driver. Hence, add property POWER_SUPPLY_PROP_SET_SHIP_MODE
to force the device into ship-mode.

CRs-Fixed: 1092969
Change-Id: I43893355db063d99b6faf965093fad74ec0c9253
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>