[IA64] make IOMMU respect the segment boundary limits

IA64's IOMMU implementation allocates memory areas spanning LLD's segment
boundary limit.  It forces low level drivers to have a workaround to adjust
scatter lists that the IOMMU builds.

We are in the process of making all the IOMMUs respect the segment boundary
limits to remove such work around in LLDs.  This patch is for IA64's IOMMU.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>