Add a OMAP4 specific GMPC nand config for pcm049 and phyCARD-A-XL2 to increase
performance. Also add the possiblility to pass a board GPMC nand config.
Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>