arm64: dts: mt7622: add a bluetooth 5 device node

Add a built-in bluetooth 5 support for MT7622.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Acked-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>