[MTD] [NAND] drivers/mtd/nand/nandsim.c needs div64.h

drivers/mtd/nand/nandsim.c: In function 'divide':
drivers/mtd/nand/nandsim.c:462: error: implicit declaration of function 'do_div'

Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>