usb: xhci-mtk: fix ISOC error when interval is zero

[ Upstream commit 87173acc0d8f0987bda8827da35fff67f52ad15d ]

If the interval equal zero, needn't round up to power of two
for the number of packets in each ESIT, so fix it.

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>