arm: dts: mt7623: add musb device nodes

MT7623 has an musb controller that is compatible with the one from MT2701.

Signed-off-by: Sungbo Eo <mans0n@gorani.run>
Tested-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20210830155903.13907-2-mans0n@gorani.run


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>