[MTD] removed unused #include <version.h>

The drivers below do not use LINUX_VERSION_CODE nor KERNEL_VERSION.
  drivers/mtd/maps/amd76xrom.c
  drivers/mtd/maps/ck804xrom.c
  drivers/mtd/maps/esb2rom.c

This patch removes the said #include <version.h>.

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>