iommu/amd: Update irq_remapping_alloc to use IOMMU lookup helper function

To allow IOMMU rlookup using both PCI segment and device ID.

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/20220706113825.25582-17-vasant.hegde@amd.com


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