rapidio/tsi721: add check for overlapped IB window mappings

Add check for attempts to request mapping of inbound RapidIO address
space that overlaps with existing active mapping windows.

Tsi721 device does not support overlapped inbound windows and SRIO
address decoding behavior is not defined in such cases.

This patch is applicable to kernel versions starting from v3.7.

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