sf: winbond: Add support for W25Q256

Add support for Winbond W25Q256 SPI flash.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>

drivers/mtd/spi/winbond.c

@@ -62,6 +62,11 @@ static const struct winbond_spi_flash_params winbond_spi_flash_table[] = {
 		.nr_blocks		= 256,
 		.name			= "W25Q128",
 	},
+	{
+		.id			= 0x4019,
+		.nr_blocks		= 512,
+		.name			= "W25Q256",
+	},
 	{
 		.id			= 0x5014,
 		.nr_blocks		= 128,