ARM: Kirkwood: Fix typo in the definition of ix2-200 rebuild LED

In the conversion to pinctrl, an error in the pins for the rebuild
LED was introduced. This patch assigns the correct pins and includes
the correct name for the LED in kirkwood-iomega_ix2_200.dts.

Signed-off-by: Nigel Roberts <nigel@nobiscuit.com>
Cc: <stable@vger.kernel.org> # v3.8.x
Signed-off-by: Jason Cooper <jason@lakedaemon.net>