ARM: dts: sunxi: Switch to new GPIOs properties for i2c-gpio

The i2c-gpio driver uses named gpios now and the array of GPIOs is
deprecated. Switch to the new binding.

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