sunxi: gpio: add missing compatible strings

The sunxi GPIO driver is missing some compatible strings for recent
SoCs. While most of the sunxi GPIO code seems to not rely on this (and
so works anyway), the sunxi_name_to_gpio() function does and fails at
the moment (for instance when resolving the MMC CD pin name).
Add the compatible strings for the A64 and V3s, which were missing
from the list. This now covers all pinctrl nodes in our own DTs.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>