ARM: dts: sun8i: reference-design: use AXP223 DTSI

Previously, the sun8i tablets used everything declared in AXP221 DTSI
while they have an AXP223 PMIC.

This corrects that so the sun8i tablets can get some features the AXP223
has (at the moment, ability to have 100mA as maximal current on VBUS
power supply).

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>