[MTD] Remove iq80310 map driver

The iq80310 mtd map driver depends on ARCH_IQ80310, which isn't
defined anywhere in the tree (as we don't have 80310 support), and
furthermore, everything the driver does can be done with physmap
instead.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>