iommu/mediatek: Add PCIe support

Currently the code for of_iommu_configure_dev_id is like this:

static int of_iommu_configure_dev_id(struct device_node *master_np,
                                     struct device *dev,
                                     const u32 *id)
{
       struct of_phandle_args iommu_spec = { .args_count = 1 };

       err = of_map_id(master_np, *id, "iommu-map",
                       "iommu-map-mask", &iommu_spec.np,
                       iommu_spec.args);
...
}

It supports only one id output. BUT our PCIe HW has two ID(one is for
writing, the other is for reading). I'm not sure if we should change
of_map_id to support output MAX_PHANDLE_ARGS.

Here add the solution in ourselve drivers. If it's pcie case, enable one
more bit.

Not all infra iommu support PCIe, thus add a PCIe support flag here.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20220503071427.2285-23-yong.wu@mediatek.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>