ARM: dts: sun8i: h2+: add SY8113B regulator used by Orange Pi Zero board

Orange Pi Zero board has a SY8113B regulator, which is controlled via
GPIO and capable of outputing 1.1V when the PL6 GPIO is set to output 0
or 1.3V when the PL6 GPIO is set to input or output 1, and the output is
the power supply of the ARM cores in H2+ SoC.

Add the device tree node of this regulator and set the cpu's cpu-supply
property to it.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
[wens@csie.org: rename regulator node name and label]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>