ARM: dt: sun6i: Add #address-cells and #size-cells to i2c controller nodes

dtc was giving warnings for missing #address-cells and #size-cells for
the new sun6i-a31-hummingbird.dts, which has a i2c-based rtc device.

This patch adds the properties for all i2c controller nodes for sun6i.

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