ARM: dts: sun8i: a23/a33: Add R_I2C Controller

The A23 and A33 both have an I2C controller in the ARISC domain, that share
the same pins with the RSB bus.

Even if it's an unusual configuration, that device can be used to drive the
PMIC, so let's use it.

Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>