add further OF support to plat_nand driver

chip-delay, bbt-use-flash and width

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
first step to plumbing in NAND support for TS-7800 DT platform

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
add support to read number of chips from DT for plat_nand

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
got the NAND working...it seems

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>