spi: spi-qpic-snand: add support for 8 bits ECC strength

Even though the hardware supports 8 bits ECC strength, but that is not
handled in the driver yet. This change adds the missing bits in order
to allow using the driver with chips which require 8 bits ECC strength.

No functional changes intended with regard to the existing 4 bits ECC
strength support.

Tested on an IPQ9574 platform using a GigaDevice GD5F2GM7REYIG chip.

Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://patch.msgid.link/20250702-qpic-snand-8bit-ecc-v2-2-ae2c17a30bb7@gmail.com


Signed-off-by: Mark Brown <broonie@kernel.org>