rapidio: add new RapidIO DMA interface routines

Add RapidIO DMA interface routines that directly use reference to the mport
device object and/or target device destination ID as parameters.
This allows to perform RapidIO DMA transfer requests by modules that do not
have an access to the RapidIO device list.

Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Stef van Os <stef.van.os@prodrive-technologies.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>