power: supply: bq25890: Add new linux,iinlim-percentage property

power: supply: bq25890: Add new linux,iinlim-percentage property

Some devices, such as the Lenovo Yoga Tab 3 Pro (YT3-X90F) have
multiple batteries with a separate bq25890 charger for each battery.

This requires the maximum current the external power-supply can deliver
to be divided over the chargers. The Android vendor kernel shipped
on the YT3-X90F divides this current with a 40/60 percent split so that
batteries are done charging at approx. the same time if both were fully
empty at the start.

Add support for a new "linux,iinlim-percentage" percentage property which
can be set to indicate that a bq25890 charger should only use that
percentage of the external power-supply's maximum current.

So far this new property is only used on x86/ACPI (non devicetree) devs,
IOW it is not used in actual devicetree files. The devicetree-bindings
maintainers have requested properties like these to not be added to the
devicetree-bindings, so the new property is deliberately not added
to the existing devicetree-bindings.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>