Backport request for "powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains"

Hello,

Commit a940904443e432623579245babe63e2486ff327b ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains") fixes a regression that prevents attaching PCI devices to the vfio-pci driver on PPC64. Its inclusion in 6.1 would open the door for restoring VFIO and KVM PCI passthrough support on distros that rely on this LTS kernel.

Thanks, Shawn