mtd: Define MLC Flash as a different flash type

MLC NAND Flash has a different cell structure and differs in
functioning than the SLC NAND Flash. Hence we are considering it as
a different Flash type.
Signed-off-by: NRohit H.S <rohit.hs@samsung.com>
Signed-off-by: NRaghav Gupta <gupta.raghav@samsung.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

include/mtd/mtd-abi.h

@@ -52,6 +52,7 @@ struct mtd_oob_buf64 {
 #define MTD_NANDFLASH		4
 #define MTD_DATAFLASH		6
 #define MTD_UBIVOLUME		7
+#define MTD_MLCNANDFLASH	8
 
 #define MTD_WRITEABLE		0x400	/* Device is writeable */
 #define MTD_BIT_WRITEABLE	0x800	/* Single bits can be flipped */