usb: host: xhci-mtk: avoid runtime suspend when removing hcd

usb: host: xhci-mtk: avoid runtime suspend when removing hcd

When runtime suspend was enabled, runtime suspend might happen
when xhci is removing hcd. This might cause kernel panic when hcd
has been freed but runtime pm suspend related handle need to
reference it.

Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Reviewed-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200624135949.22611-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>