clk: sunxi: Add NAND clocks and resets

clk: sunxi: Add NAND clocks and resets

Currently NAND clock setup is done in board code, both in SPL and in
U-Boot proper. Add the NAND clocks/resets here so they can be used by
the "full" NAND driver once it is converted to the driver model.

The bit locations are copied from the Linux CCU drivers.

Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>