ARM: pxa: prune unused device support

pxa3xx is now DT-only, and the remaining pxa2xx board files
only use a subset of the possible devices, so remove all
definitions that are not referenced any more.

Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>