Synopsys OUT EP improvements:
Synopsys OUT EP improvements:

- Use register based XFRSIZ to determine transfer complete
  (xfer->queued_len and xfer->short_packet were deleted)
- Pop out as many RxFIFO data entries as available within a IRQ call
- less application interruption due to XFRC calls

hathach/tinyusb,hathach/tinyusb,hathach/tinyusb