ARM: dts: sun8i: h3: Add SY8106A regulator to Orange Pi PC

Add SY8106A regulator to r_i2c bus and enable the r_i2c bus on
Orange Pi PC, then set the power supply of the ARM cores to this
regulator, in order to enable DVFS.

Signed-off-by: Ondrej Jirman <megous@megous.com>
[Icenowy: Enable DVFS in this patch, slight changes and change commit
 message]
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>