mtd: drop ceiva map driver

It's a Ceiva/Polaroid PhotoMax Digital Picture Frame. Support for it was
commited before 2.6.12-rc2, current git contains no functional changes
since it's start. Driver containing MTD support for that board was
broken for some time already.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>