iommu/vt-d: Move include/linux/intel-iommu.h under iommu

This header file is private to the Intel IOMMU driver. Move it to the
driver folder.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Steve Wahl <steve.wahl@hpe.com>
Link: https://lore.kernel.org/r/20220514014322.2927339-8-baolu.lu@linux.intel.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>