The driver sets the fuel gauge to continuous monitoring on startup, for
the models that support this. When the board shuts down, the chip remains
in that mode, causing a few mA drain on the battery every 2 or 10 seconds.

This patch registers a shutdown handler that turns off the monitoring to
prevent this battery drain.
Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>