- config option CONFIG_CRASH_DUMP

- Made it dependent on HIGHMEM.  This is required as capture kernel treats
  the previous kernel's memory as high memmory and stitches a PTE for
  accessing it.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>