sunxi: gpio: Add compatible strings for all supported SoCs

We want to use driver-model/fdt with other model SoCs too, so add
compatible strings for the other SoCs to the dm sunxi gpio code.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Acked-by: Ian Campbell <ijc@hellion.org.uk>