usb: xhci-mtk: supports remote wakeup for mt2712 with two xHCI IPs

The old way of usb wakeup only supports platform with single xHCI IP,
such as mt8173, but mt2712 has two xHCI IPs, so rebuild its flow and
supports the new glue layer of usb wakeup on mt2712 which is different
from mt8173.
Due to there is a hardware bug with the LINE STATE wakeup mode on
mt8173 which causes wakeup failure by low speed devices, and also
because IP SLEEP mode can cover all functions of LINE STATE mode,
it is unused in fact, and will not support it later, so remove it at
the same time.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>