sunxi: Enable a bunch of commands by default on sunxi

Recently a set of CONFIG_CMD_FOO defines was moved from being defined
in config_distro_defaults to Kconfig, and added to all sunxi defconfigs
to compensate.

Instead of explictly selecting these in all sunxi defconfigs,
simply always select these for sunxi boards. This makes the defconfigs
simpler and ensures a consistent set of available commands across all
sunxi boards.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>