[MTD] [OneNAND] Add OMAP2 / OMAP3 OneNAND driver

This driver had resided in the OMAP tree but is now to be in MTD.

Original authors were:
	Jarkko Lavinen <jarkko.lavinen@nokia.com> and Juha Yrjölä
	IRQ and DMA support written by Timo Teras

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>