iommu: make iommu_inclusive_mapping a suboption of dom0-iommu

iommu: make iommu_inclusive_mapping a suboption of dom0-iommu

Introduce a new dom0-iommu=map-inclusive generic option that
supersedes iommu_inclusive_mapping. The previous behavior is preserved
and the option should only be enabled by default on Intel hardware.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Julien Grall <julien.grall@arm.com>
Acked-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>