ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3 model

Cavium ThunderX2 implementation doesn't support second page in SMMU
register space. Hence, resource size is set as 64k for this model.

Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>