Revert "km_arm: enable POST for these boards"

This reverts commit a2da6163.
THis was applied by accident - a more recent version of this change
was already present, see commit
9400f8fa   2011-10-05 22:03:11 +0200   km_arm: enable POST for these boards

Signed-off-by: Wolfgang Denk <wd@denx.de>