usb: xhci-mtk: supports bandwidth scheduling with multi-TT

Supports LowSpeed and FullSpeed INT/ISOC bandwidth scheduling
with USB multi-TT

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>