mtd: nand: fix nand_read_subpage function

Now that we moved to per-partition ECC, se should always use chip->cur_ecc
instead of chip->ecc unless we really want to get default ECC config
set for the whole chip.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Reported-by: Yassin Jaffer <yassinjaffer@gmail.com>
mtd: nand: add Samsung's K9GBG08U0B to nand_ids table

Add the full description of the Samsung K9GBG08U0B NAND chip in the
nand_ids table so that we can later use the NAND ECC infos and ONFI timings
mode in controller drivers.

Signed-off-by: Petros Angelatos <petrosagg@gmail.com>