Trivial cleanup
Remove ioctl TIOCINQ
Remove unused wait queues
Remove unused field write_in_progress
Remove unused TxFifo & RxFifo
Remove unused TxCredits and MaxTxCredits
Remove unused rxBytesAvail & rxBytesRemaining
Remove unused product_info
Remove unused validDataMask
Remove unused shadow values
Remove struct moschip_serial
Remove unused flags from struct moschip_port; remove mos7703_break as it became a no-op.
Remove unused usb-related stuff