power: supply: max17042_battery: Add support for the TECHNOLOGY attribute

The max17042 is intended for Li-Ion or Li-Po batteries, add a TECHNOLOGY
attribute to reflect this. Note this is hardcoded to Li-Ion as there is
no way to tell the difference, and Lithium-Ion Polymer batteries are
a sub-family of Lithium-Ion so Li-Ion technically is correct for both.

Using Li-Ion for both is already done by many drivers and is much
better then not providing any technology info at all.

Suggested-by: Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>