power: charger: need sometime to handle the usb disconnecting events

When being completely charged in the offmode charging and pulling out TA
from sleep condition, I gave 1 sec. delay until entering sleep condition again,
in order to prevent the phenomenon that a device doesn't turn off.

We need sometime for an userspace application to handle the usb disconnection
events. There is no effect of power consumption.

Change-Id: I0851cc2b47c3780fd68d3e8965fd0d6f5b7e8312