mtd: spi-nor: Do not change nor->addr_nbytes at SFDP parsing time

At the SFDP parsing time we should not change members of struct spi_nor,
but instead fill members of struct spi_nor_flash_parameters which could
later on be used by callers. The caller will then decide if SFDP params
should be used and more importantly when they should be used. Clean the
code flow and don't initialize nor->addr_nbytes at SFDP parsing time.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Tested-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Reviewed-by: Michael Walle <michael@walle.cc>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20220725092505.446315-4-tudor.ambarus@microchip.com