mfd: axp20x: Rename ADC register name IPSOUT to APS

The datasheet for axp209 names the ADC as IPSOUT for the value
registers, but names it APS for the toggle bit. Assuming the
ADCs are on the input side, naming it APS is better.

Also get rid of the extra 'HIGH', as that represents the high
bits of the reading, and is noted by the _H suffix.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
hwmon: AXP20x: Add support for basic voltage/current/temperature ADCs

AXP202 and AXP209 can report voltages and current readings for its
various power inputs, the LiPo battery, and also the chip's internal
temperature. Add basic support for these sensors.

This leaves out ADCs that require pinctrl/gpio support, or configurable
sensors such as the TS pin ADC for external temperature sensors.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
add axp20x prefix
Revert "add axp20x prefix"

This reverts commit 116292fbb01a1864d79ebe7b5d8ba5af5768016c.