sf: spansion: Add support for S25FL256S

Add support for Spansion S25FL256S SPI flash.

Signed-off-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/drivers/mtd/spi/spansion.c b/drivers/mtd/spi/spansion.c
index 9a114ac..32b76e0 100644
--- a/drivers/mtd/spi/spansion.c
+++ b/drivers/mtd/spi/spansion.c
@@ -96,6 +96,13 @@
 		.nr_sectors = 256,
 		.name = "S25FL129P_64K",
 	},
+	{
+		.idcode1 = 0x2019,
+		.idcode2 = 0x4d01,
+		.pages_per_sector = 256,
+		.nr_sectors = 512,
+		.name = "S25FL256S",
+	},
 };
 
 struct spi_flash *spi_flash_probe_spansion(struct spi_slave *spi, u8 *idcode)