power: supply: axp288_charger: Add missing newlines to some messages

Add missing (terminating) "\n"-s to some dev_dbg messages.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>