iommu/mediatek: Initialise/Remove for multi bank dev

The registers for each bank of the IOMMU base are in order, delta is
0x1000. Initialise the base for each bank.

For all the previous SoC, we only have bank0. thus use "do {} while()"
to allow bank0 always go.

When removing the device, Not always all the banks are initialised, it
depend on if there is masters for that bank.

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/20220503071427.2285-34-yong.wu@mediatek.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>