mtd: nand: make Samsung SLC NAND usable again

mtd: nand: make Samsung SLC NAND usable again

commit c51d0ac59f24 ("mtd: nand: Move Samsung specific init/detection
logic in nand_samsung.c") introduced a regression for Samsung SLC NAND
chips. Prior to this commit chip->bits_per_cell was initialized by calling
nand_get_bits_per_cell() before using nand_is_slc().
With the offending commit this call is skipped, leaving
chip->bits_per_cell cleared to zero when the manufacturer specific
'.detect' function calls nand_is_slc() which in turn interprets
bits_per_cell != 1 as indication for an MLC chip.
The effect is that e.g. a K9F1G08U0F NAND chip is falsely detected as
MLC NAND with 4KiB page size rather than SLC with 2KiB page size.

Add a call to nand_get_bits_per_cell() before calling the .detect hook
function in nand_manufacturer_detect(), so that the nand_is_slc()
calls in the manufacturer specific code will return correct results.

Fixes: c51d0ac59f24 ("mtd: nand: Move Samsung specific init/detection logic in nand_samsung.c")
Cc: <stable@vger.kernel.org>
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>