iommu/amd: Do not Invalidate IRT when IRTE caching is disabled

iommu/amd: Do not Invalidate IRT when IRTE caching is disabled

With the Interrupt Remapping Table cache disabled, there is no need to
issue invalidate IRT and wait for its completion. Therefore, add logic
to bypass the operation.

Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Suggested-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20230530141137.14376-5-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>