mtd: spi-nor: core: set mtd->eraseregions for non-uniform erase map

Some of Infineon SPI NOR flash devices support hybrid sector layout that
overlays 4KB sectors on a 256KB sector and SPI NOR framework recognizes
that by parsing SMPT and construct params->erase_map. The hybrid sector
layout is similar to CFI flash devices that have small sectors on top
and/or bottom address. In case of CFI flash devices, the erase map
information is parsed through CFI table and populated into
mtd->eraseregions so that users can create MTD partitions that aligned
with small sector boundaries. This patch provides the same capability to
SPI NOR flash devices that have non-uniform erase map.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Reviewed-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/35d0962986e493b06c13bdf7ada8130a9966dc02.1708404584.git.Takahiro.Kuwano@infineon.com
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>