iommu: dart: Support different variants with different registers

T8110 has a new register layout. To accommodate this, first move all the
register offsets to the hw structure, and rename all the existing
registers to DART_T8020_*.

Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20230113105029.26654-7-marcan@marcan.st


Signed-off-by: Joerg Roedel <jroedel@suse.de>