mtd: spi-nor: ids: Add is25wp256 chip

Add is25wp256, chip to spi-nor id table.

Tested on SiFive FU540 board.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/mtd/spi/spi-nor-ids.c b/drivers/mtd/spi/spi-nor-ids.c
index 6996c0a..04db986 100644
--- a/drivers/mtd/spi/spi-nor-ids.c
+++ b/drivers/mtd/spi/spi-nor-ids.c
@@ -128,6 +128,8 @@
 			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
 	{ INFO("is25wp128",  0x9d7018, 0, 64 * 1024, 256,
 			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
+	{ INFO("is25wp256",  0x9d7019, 0, 64 * 1024, 512,
+			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
 #endif
 #ifdef CONFIG_SPI_FLASH_MACRONIX	/* MACRONIX */
 	/* Macronix */