mtd: spi-nor: add support for ISSI is25lp256

Add support for ISSI is25lp256 spi nor flash.
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: Angelo Dureghello <angelo@sysam.it>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>
Signed-off-by: NBoris Brezillon <boris.brezillon@bootlin.com>

drivers/mtd/spi-nor/spi-nor.c

@@ -1049,6 +1049,8 @@ static const struct flash_info spi_nor_ids[] = {
 			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
 	{ "is25lp128",  INFO(0x9d6018, 0, 64 * 1024, 256,
 			SECT_4K | SPI_NOR_DUAL_READ) },
+	{ "is25lp256",  INFO(0x9d6019, 0, 64 * 1024, 512,
+			SECT_4K | SPI_NOR_DUAL_READ) },
 
 	/* Macronix */
 	{ "mx25l512e",   INFO(0xc22010, 0, 64 * 1024,   1, SECT_4K) },