iommu/amd: Report irq remapping through IOMMU-API

Report the availability of irq remapping through the
IOMMU-API to allow KVM device passthrough again without
additional module parameter overrides.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 33f144f..312dd4d 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3353,6 +3353,8 @@
 	switch (cap) {
 	case IOMMU_CAP_CACHE_COHERENCY:
 		return 1;
+	case IOMMU_CAP_INTR_REMAP:
+		return irq_remapping_enabled;
 	}
 
 	return 0;