power: supply: bq24190_charger: Enable devicetree config

Add get_config(). Rename set_mode_host() to set_config().
Call get_config() and hw_init() after power_supply_register().
No functional changes.

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