Document the devicetree bindings in 8250.txt for MediaTek BTIF
controller which could be found on MT7622 and MT7623 SoC.
Signed-off-by: NSean Wang <sean.wang@mediatek.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>