Adds RapidIO enumeration/discovery.

The core code implements enumeration/discovery, management of
devices/resources, and interfaces for RIO drivers.
Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>