mtd: spinand: Fix max_bad_eraseblocks_per_lun info in memorg

The 1Gb Macronix chip can have a maximum of 20 bad blocks, while
the 2Gb version has twice as many blocks and therefore the maximum
number of bad blocks is 40.

The 4Gb GigaDevice GD5F4GQ4xA has twice as many blocks as its 2Gb
counterpart and therefore a maximum of 80 bad blocks.

Fixes: 377e517b ("mtd: nand: Add max_bad_eraseblocks_per_lun info to memorg")
Reported-by: Emil Lenngren <emil.lenngren@gmail.com>
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>