sunxi: axp: Remove non driver-model support from the axp gpio code

sunxi: axp: Remove non driver-model support from the axp gpio code

Now that all sunxi boards are using driver-model for gpio (*), we can remove
the non driver-model support from the axp gpio code, and the glue to call
into the axp gpio code from the sunxi_gpio non driver-model code.

*) For the regular u-boot build, SPL still uses non driver-model gpio for
now, but the SPL never uses axp gpios support and we were already not building
axp-gpio support for the SPL.

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