mediatek: mt8173: apply MULTI_CONSOLE framework

- Switch uart driver from Mediatek 8250 to TI 16550
- Enable MULTI_CONSOLE

Signed-off-by: kenny liang <kenny.liang@mediatek.com>
Change-Id: Ie3948d9e64d05d29a1f69592792e277b680c4ed4
4 files changed