power: supply: bq24190_charger: Deprecate battery class and replicate its features in charger

The driver was registering two classes, bq24190-battery & -charger.
Because the power supply framework cannot surface features from multiple
drivers in a single class, a fuel gauge driver would create a third class,
which some power management utilities cannot see.

Deprecate the -battery class for future removal and replicate its features
in -charger. Set /sys/class...-charger/online = pg_stat && !batfet_disable.
If device_property "omit-battery-class" is set, don't register -battery.

Cc: Tony Lindgren <tony@atomide.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Liam Breck <kernel@networkimprov.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>