power: supply: add AC power supply driver for AXP813

AXP813 and AXP803 PMICs can control input current and minimum voltage.

Both of these values are configurable.

Signed-off-by: Oskari Lemmela <oskari@lemmela.net>
Reviewed-by: Quentin Schulz <quentin.schulz@bootlin.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>