sf: spansion: Update the name for S25FL256S flash

As the per the ID tabl the flash is under Uniform 64-kB sector
architecture, hence updated with proper name.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>

drivers/mtd/spi/spansion.c

@@ -108,7 +108,7 @@ static const struct spansion_spi_flash_params spansion_spi_flash_table[] = {
 		.idcode2 = 0x4d01,
 		.pages_per_sector = 256,
 		.nr_sectors = 512,
-		.name = "S25FL256S",
+		.name = "S25FL256S_64K",
 	},
 };