mtd: remove obsolete JEDEC mapping drivers

JEDEC device support was removed in v2.6.22. (It had been marked as
BROKEN (indirectly) since at least v2.6.12.)

When it was removed the two JEDEC mapping drivers that depended on it
should have been removed too. Do so now.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>