iommu/amd: Introduce struct amd_ir_data.iommu

Add a pointer to struct amd_iommu to amd_ir_data structure, which
can be used to correlate interrupt remapping data to a per-PCI-segment
interrupt remapping table.

Co-developed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20220706113825.25582-18-vasant.hegde@amd.com


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