[ARM] orion5x: Base support for DNS-323 rev C1

This patch adds the base support for this new HW revision to the existing
dns323-setup.c file. The SoC seems to be the same as rev B1, the GPIOs
are all wired differently though and the fan control isn't i2c based
anymore.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>