mtd: rawnand: prepare the removal of ONFI/JEDEC parameter pages

The NAND chip parameter page is statically allocated within the
nand_chip structure, which reserves a lot of space. Even not ONFI nor
JEDEC chips have it embedded. Also, only a few parameters are actually
read from the parameter page after the detection.

To prepare to the removal of such huge structure, a small NAND parameter
structure is allocated statically and contains only very few members
that are generic to all chips and actually used elsewhere in the code.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>