mtd: spi-nor: spansion: Enable dual and quad read for s25fl256s0

The s25fl256s0 supports dual and quad read like s25fl256s1.
Enable it by adding SPI_NOR_DUAL_READ and SPI_NOR_QUAD_READ
flags to the flash_info entry. Tested with the device and
confirmed that is working.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@cypress.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>