iommu/tegra: smmu: Support variable MMIO ranges/blocks

Presently SMMU registers are located in discontiguous 3 blocks. They
are interleaved by MC registers. Ideally SMMU register blocks should
be in an independent one block, but it is too late to change this H/W
design. In the future Tegra chips over some generations, it is
expected that some of register block "size" can be extended towards
the end and also more new register blocks will be added at most a few
blocks. The starting address of each existing block won't change. This
patch allocates multiple number of register blocks dynamically based
on the info passed from DT. Those ranges are verified in the
accessors{read,write}. This may sacrifice some performance because a
new accessors prevents compiler optimization of a fixed size register
offset calculation. Since SMMU register accesses are not so frequent,
this would be acceptable. This patch is necessary to unify
"tegra-smmu.ko" over some Tegra SoC generations.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>