power: android-battery: Fix battery alarm timer not modified at suspend

     - Alarm Timer driver is suspended before battery driver, so alarm
       timer was not changed to slow poll speed at suspend.  Use PM
       notifiers instead.
     - If charger is connected, keep 1 min alarm timer.

Signed-off-by: HongMin Son <hongmin.son@samsung.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Change-Id: Id0f3bda5d0749fd90f1964073bc30c1a73fc317f