sunxi: Complete i2c support for each supported platform

Sunxi platforms come with at least 3 TWI (I2C) controllers and some platforms
even have up to 5. This adds support for every controller on each supported
platform, which is especially useful when using expansion ports on single-board-
computers.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>