drivers: charger: charger_max20335: handle charger notifications

Add support for status and online notification properties.
Fire these notifications from int_routine_handler work directly.
Such approach makes the code cleaner and does not affect overall
max20335 interrupt processing performance. However application code
processing these notifications cannot be blocking.

Signed-off-by: Lukasz Madej <l.madej@grinn-global.com>