mtd: onenand: omap2: Configure driver from DT

mtd: onenand: omap2: Configure driver from DT

Move away from platform data configuration and use pure DT approach.

Use generic probe function to deal with OneNAND node and remove now useless
gpmc_probe_onenand_child function. Import sync mode timing calculation
function from mach-omap2/gpmc-onenand.c

Signed-off-by: Ladislav Michl <[email protected]>
Reviewed-by: Peter Ujfalusi <[email protected]>
Tested-by: Tony Lindgren <[email protected]>
Tested-by: Aaro Koskinen <[email protected]>
Acked-by: Roger Quadros <[email protected]>
Signed-off-by: Boris Brezillon <[email protected]>