ANDROID: KVM: arm64: Don't always update IOMMUs from module_change_host_page_prot

Host stage-2 changes initiated from module may not need to trigger IOMMU
updates as DMA attacks is out of scope for their threat model. As such,
don't bother calling into the IOMMU layer from
module_change_host_page_prot if not requested by the module.

While at it, make sure to trigger an IOMMU update during MMIO
donations in the normal set_owner_locked() path.

Bug: 278749606
Bug: 322736772
Change-Id: Idaeecb3983d9d1ee753845ec2b764d32c762f35a
Signed-off-by: Quentin Perret <qperret@google.com>