mtd: decommission the NAND museum

The MTD subsystem has its own small museum of ancient NANDs in a form of the
CONFIG_MTD_NAND_MUSEUM_IDS configuration option. The museum contains stone age
NANDs with 256 bytes pages, as well as iron age NANDs with 512 bytes per page
and up to 8MiB page size.

It is with great sorrow that I inform you that the museum is being
decommissioned. The MTD subsystem is out of budget for Kconfig options and
already has too many of them, and there is a general kernel trend to simplify
the configuration menu.

We remove the stone age exhibits along with closing the museum, but some of the
iron age ones are transferred to the regular NAND depot. Namely, only those
which have unique device IDs are transferred, and the ones which have
conflicting device IDs are removed.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>