ARM: sunxi: dt: Convert to the new i2c compatibles

Switch the device tree to the new compatibles introduced in the i2c drivers
to have a common pattern accross all Allwinner SoCs.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>