sunxi: nand: Add pinmux and clock settings for NAND support

To enable NAND flash in sunxi SPL,
pins 0-6, 8-22 and 24 on port C are configured.

Signed-off-by: Karol Gugala <kgugala@antmicro.com>
Signed-off-by: Piotr Zierhoffer <pzierhoffer@antmicro.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>