Revert "max77693: Standardize the output of the "online" property"

This reverts commit 1a05356029493b29f866cf04f7550243ef3ae687, the
enumerator breakage introduced by change Iafbd9fb45253b02d539ac0ba114f57b3bf9eeed4
can be reverted cleanly without further impact and it's a cleaner fix

Change-Id: I351c320f98691241fbe321a0b1ac54152802deb4