mtd: spi-nor: Fix mtd size for s3an flashes

As it was before the blamed commit, s3an_nor_scan() was called
after mtd size was set with params->size, and it overwrote the mtd
size value with '8 * nor->page_size * nor->info->n_sectors' when
XSR_PAGESIZE was set. With the introduction of
s3an_post_sfdp_fixups(), we missed to update the mtd size for the
s3an flashes. Fix the mtd size by updating both nor->params->size,
(which will update the mtd_info size later on) and nor->mtd.size
(which is used in spi_nor_set_addr_width()).

Fixes: 641edddb ("mtd: spi-nor: Add s3an_post_sfdp_fixups()")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20211207140254.87681-2-tudor.ambarus@microchip.com