Armadillo500 Correct bus length for SMSC9118 on board chip.

The SMSC9118 network chip is connected to the data bus with a 16 bit
interface, not 32 as early suggested.
Signed-off-by: Alberto Panizzo <maramaopercheseimorto@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>