Change "select DMAR" to "select INTEL_IOMMU"

Commit d3f13810 ("iommu: Rename the DMAR and INTR_REMAP config
options") changed all references to DMAR in Kconfig files to INTEL_IOMMU
(and, likewise, changed the references to CONFIG_DMAR everywhere else
to CONFIG_INTEL_IOMMU). That commit missed one "select DMAR" statement
in ia64's Kconfig file. Change that one too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Tony Luck <tony.luck@intel.com>