OMAP2: add board file for Nokia N800 and N810

Add board file for Nokia N800 and N810 devices. Currently only serial ports,
onenand and spi are configured, more to come later.

Tested on Nokia N800.

Signed-off-by: Kalle Valo <kalle.valo@iki.fi>
Signed-off-by: Tony Lindgren <tony@atomide.com>