dfu: set poll timeout to 128 ms to reduce EPIPE errors
The previous 10 ms poll timeout creates ERROR_PIPE errors when the octsim is connected to a more busy bus. E.g. when a network device is connected to the same bus or when flashing multiple OCTSIMs at the same time.
From usb captures 70 ms should be already enough, but adding an additional safety margin. It is unclear why the EPIPE errors happens.
