iommu/apple-dart: Add 4-level page table support

iommu/apple-dart: Add 4-level page table support

The T8110 variant DART implementation on T602x SoCs indicates an IAS of
42, which requires an extra page table level. The extra level is
optional, but let's implement it.

Later it might be useful to restrict this based on the actual attached
devices, since most won't need that much address space anyway.

Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Sven Peter <sven@kernel.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Link: https://lore.kernel.org/r/20250821-apple-dart-4levels-v2-3-e39af79daa37@jannau.net
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>