dt-bindings: phy-mtk-tphy: add properties of address mapping and clocks

1. add the address mapping related properties;
2. make "ref" clock optional, and add optional clock "da_ref";
3. add the banks layout of TPHY V1 and V2;

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Weijie Gao <weijie.gao@mediatek.com>