In cases when the info FIFO fills, it was possible for
in_pkt_info_tvalid to be asserted then on the next cycle
in_pkt_info_tready would deassert, in which case the input would be
dropped. This change ensures that tvalid remains asserted until tready
deasserts.
Original-commit: 6d2e9f983ae94d2e1e6866c34b3c87374a349631