iommu/arm-smmu: fix incorrect use of S2CR_TYPE_SHIFT

There is already S2CR_TYPE_SHIFT in S2CR_TYPE_TRANS macro, so drop the
second shift. Note that, since S2CR_TYPE_SHIFT is 0x0, there is no
functional change introduced by this patch.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>