power: step-chg-jeita: use power_supply notifier for time hysteresis

The step-charging flow rejects processing of events if it sees one within
certain time (hysteresis). However, it holds a wake-lock until its actual
processing time expires, this prevents the system from going into suspend.

Fix this by removing the hysteresis based event rejection, instead only
rely on the periodic step-chg specific wake-up events to process.

Change-Id: I4f720c90e92072264663edb18062502c3feba576
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>