max1720x_battery: sync POR model reload handler

1. Handle POR in non-boot up process (http://pa/1982268)
2. POR reload when model_ok (http://pa/1992177)
3. cleanup for 189251616 (http://pa/2015548

)

Bug: 189251616
Signed-off-by: Jenny Ho <hsiufangho@google.com>
Change-Id: I141b6551992e77ba179dda5807acc8af88d86e4f