iommu/arm-smmu-v3: Support 52-bit physical address

Implement SMMUv3.1 support for 52-bit physical addresses. Since a 52-bit
OAS implies 64KB translation granule support, permitting level 1 block
entries there is simple, and the rest is just extending address fields.

Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>