iommu/mtk: Remove iommu_ops pgsize_bitmap

iommu/mtk: Remove iommu_ops pgsize_bitmap

This driver just uses a constant, put it in domain_alloc_paging
and use the domain's value instead of ops during finalise.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/5-v2-68a2e1ba507c+1fb-iommu_rm_ops_pgsize_jgg@nvidia.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>