mtd: nand: renumber conflicting BBT flags

The NAND_USE_FLASH_BBT_NO_OOB and NAND_CREATE_EMPTY_BBT flags conflict
with the NAND_BBT_SCANBYTE1AND6 and NAND_BBT_DYNAMICSTRUCT flags,
respectively. This change will allow us to utilize these options
independently.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>