iommu/mediatek: Add SUB_COMMON_3BITS flag

iommu/mediatek: Add SUB_COMMON_3BITS flag

In prevous SoC, the sub common id occupy 2 bits. the mt8195's sub common
id has 3bits. Add a new flag for this. and rename the previous flag to
_2BITS. For readable, I put these two flags together, then move the
other flags. no functional change.

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/20220503071427.2285-16-yong.wu@mediatek.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>