mtd: rawnand: sunxi: add has_ecc_block_512 capability

mtd: rawnand: sunxi: add has_ecc_block_512 capability

The H616 controller can't handle 512 bytes ECC block size. The
NFC_ECC_BLOCK_512 bit disappeared in H6, and NDFC_RANDOM_EN took its
place.

So, add has_ecc_block_512 capability to only set this bit on SoC having
it.

No functional change.

Signed-off-by: Richard Genoud <richard.genoud@bootlin.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>