This patch makes it possible to compile Calgary in but not use it by
default. In this mode, use 'iommu=calgary' to activate it.
Signed-off-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>
Signed-off-by: NAndi Kleen <ak@suse.de>