power: supply: bq25890: Support boards with more then one charger IC

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 bq25890_charger code to use a unique name per
registered power_supply class device, rather then hardcoding
"bq25890-charger" as power_supply class device name.

Add a "-%d" prefix to the name, allocated through idr in the same way
as several other power_supply drivers are already doing this.

Note this also updates: drivers/platform/x86/x86-android-tablets.c
which refers to the charger by power_supply-class-device-name for
the purpose of setting the "supplied-from" property on the fuel-gauge
to this name.

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