mtd: nand: relax ECC parameter validation check

mtd: nand: relax ECC parameter validation check

Due to the custom handling and layouts of certain nand controllers this
validity check will always fail for certain layouts. The check
inherently depends on even chunk sizing and this is not always the
case.

Modify the check to only print a warning, instead of failing to
init the attached NAND. This allows various 8 bit and 12 ECC strength
layouts to be used.

Fixes: 68c18dae6888 ("mtd: rawnand: marvell: add missing layouts")
Signed-off-by: Aryan Srivastava <aryan.srivastava@alliedtelesis.co.nz>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>