mtd: nand: rename NAND_USE_FLASH_BBT

Recall the recently added prefix requirements:
 * "NAND_" for flags in nand.h, used in nand_chip.options
 * "NAND_BBT_" for flags in bbm.h, used in nand_chip.bbt_options
        or in nand_bbt_descr.options

Thus, I am changing NAND_USE_FLASH_BBT to NAND_BBT_USE_FLASH.

Again, this flag is found in bbm.h and so should NOT be used in the
"nand_chip.options" field.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/nand/diskonchip.c b/drivers/mtd/nand/diskonchip.c
index f70bc73..b657d7f 100644
--- a/drivers/mtd/nand/diskonchip.c
+++ b/drivers/mtd/nand/diskonchip.c
@@ -1652,7 +1652,7 @@
 	nand->ecc.mode		= NAND_ECC_HW_SYNDROME;
 	nand->ecc.size		= 512;
 	nand->ecc.bytes		= 6;
-	nand->bbt_options	= NAND_USE_FLASH_BBT;
+	nand->bbt_options	= NAND_BBT_USE_FLASH;
 
 	doc->physadr		= physadr;
 	doc->virtadr		= virtadr;