iommu/tegra-smmu: Fix tlb_mask

The "num_tlb_lines" might not be a power-of-2 value, being 48 on
Tegra210 for example. So the current way of calculating tlb_mask
using the num_tlb_lines is not correct: tlb_mask=0x5f in case of
num_tlb_lines=48, which will trim a setting of 0x30 (48) to 0x10.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200917113155.13438-2-nicoleotsuka@gmail.com


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